Digital Communications Training Systems 8085-00...582001 (8085-10) The Digital Communications...

LabVolt Series

Datasheet

Digital Communications Training Systems8085-00

Festo Didactic

en 120 V - 60 Hz

04/2020

Digital Communications Training Systems, LabVolt Series

2 © Festo Didactic

Table of ContentsGeneral Description ________________________________________________________________________________ 2Topic Coverage____________________________________________________________________________________ 3Features & Benefits ________________________________________________________________________________ 3List of Available Training Systems ____________________________________________________________________ 3Optional Equipment ________________________________________________________________________________ 3Optional Manual(s) ________________________________________________________________________________ 4Available Training Systems __________________________________________________________________________ 4Equipment Description ____________________________________________________________________________ 12Optional Equipment Description_____________________________________________________________________ 33

General DescriptionThe Digital Communications Training Systems form a complete and operational communications program, as well as a powerful educational tool. They use IC technology to implement signal modulators and demodulators that operate at standards employed in digital communications technology.

The systems are equipped with various features that enhance hands-on learning: easy access to test points, fault-insertion switches, safety shielding and full short-circuit protection, silk-screened block diagrams and component labels, and fully-integrated courseware. The Digital Communications Training Systems allow instructors to achieve a wide range of educational objectives at various levels.

The modularity of the systems allows students to quickly assemble a functioning communications network by using coaxial cables. Fully compatible signal levels and protocols are fed among modules from front panel connection points. Because the system is composed of prewired, functioning modules and connections between modules are made with shielded cables, the routing and trimming of student connections do not affect system performance and measurements. Important test points or test busses are brought out to 9-pin connectors on the front panels of modules for easy access.

The courseware included with the Digital Communications Training Systems guides students through hands-on exercises in voltage and signal measurements, alignment, calibration, and signal tracing. Clearly stated objectives, background discussions, step-by-step procedures, and review questions are included in each self-contained exercise. A troubleshooting unit included at the end of each volume enables instructors to use fault insertion switches that introduce malfunctions at the module and system levels.

The instructional modules are supported by sixteen different instrumentation modules that are separated into two groups. The first group comprises instrumentation modules that are identical to those used in the Analog Communications Training System, Series 8080. These are:

• Power Supply / Dual Audio Amplifier, Model 9401• Dual Function Generator, Model 9402• Frequency Counter, Model 9403• True RMS Voltmeter / Power Meter, Model 9404• Spectrum Analyzer, Model 9405• RF / Noise Generator, Model 9406

The second group includes the following ten instrumentation modules that are specific to the Digital Communications Training System:

• Enclosure / Supply Regulator, Model 9420• Clock Generator, Model 9421


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• Pseudo-Random Binary Sequence Generator, Model 9422• Bit Error Rate Indicator, Model 9423• Logic Analyzer, Model 9424• DC Voltmeter / DC Source, Model 9425• Low Pass Audio Filter, Model 9426• Synchronous Audio Generator, Model 9427• Signal Interruptor/Selector, Model 9428• Noise Measurement Filters, Model 9429

The Frequency Counter, True RMS Voltmeter / Power Meter, and Spectrum Analyzer mentioned above can be replaced with the Data Acquisition and Management for Telecommunications (LVDAM-COM), Model 9407. The LVDAM-COM system provides modern and versatile equipment for measuring, observing, and analyzing signals in telecommunications systems. It consists of a set of computer-based instruments running on a personal

computer under the Microsoft® Windows operating environment. The LVDAM-COM system also includes a dual trace oscilloscope with a 40 MHz bandwidth.

Topic Coverage

• Pulse Modulation and Sampling• Digital Modulation• Modems and Data Transmission• Troubleshooting

Features & Benefits

• Uses IC technology to implement signal modulators and demodulators• Correlated courseware guides students through hands-on exercises in voltage and signal measurements, alignment,

calibration, and signal tracing• Equipment protected short-circuit and over-voltage• One of the most comprehensive of its kind in the marketplace• Modular system with switches to insert faults and teach troubleshooting• Silk-screened block diagrams and component labels• LVSIM-DCOM software program also available• Estimated entire program duration: 170 hours

List of Available Training Systems

Qty DescriptionModel number

1 Digital Communications Training System ___________________________________________ 582001 (8085-10)1 Digital Communications Add-On __________________________________________________ 582008 (8085-30)1 Digital Communications Training System with LVDAM-COM ____________________________ 582018 (8085-B0)

Optional Equipment


1 Dual Trace Oscilloscope __________________________________________________________ 580849 (797-20)1 FM/PM Receiver _______________________________________________________________ 581589 (9415-10)1 Baseband Channel / Brickwall Filter _______________________________________________ 581632 (9435-00)1 Time Division Multiplexer ________________________________________________________ 581674 (9460-00)


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1 Time Division Demultiplexer ______________________________________________________ 581677 (9461-00)1 T1/CEPT PCM Transceiver _______________________________________________________ 581680 (9462-00)1 Clock Recovery ________________________________________________________________ 581683 (9463-00)1 Line Coder ____________________________________________________________________ 581686 (9464-00)1 Line Decoder __________________________________________________________________ 581689 (9465-00)1 Dust Cover (Modules) ___________________________________________________________ 587452 (9494-00)1 Dust Cover (Module Rack) _______________________________________________________ 587453 (9494-10)

Optional Manual(s)


1 Baseband Data Transmission (Student Manual) _____________________________________ 584025 (29510-00)

Available Training Systems

Digital Communications Training System582001 (8085-10)

The Digital Communications Training System consists of thirteen instructional modules supported by sixteen instrumentation modules. The instructional modules offer hands-on training in the following digital communications techniques:

• Pulse Amplitude Modulation (PAM)• Pulse Width Modulation (PWM)

• Pulse Position Modulation (PPM)• Pulse Code Modulation (PCM)• Differential Pulse Code Modulation (DPCM)• Delta and Continuously Variable Slope Delta (CVSD) Modulation• Amplitude Shift Keying (ASK)• Frequency Shift Keying (FSK)• Binary Phase Shift Keying (BPSK)

Optional instructional modules can be added to the Digital Communications Training System to study baseband data transmission. These instructional modules allow hands-on training in the following techniques:

• Time-Division Multiplexing (TDM)• Serial data transmission over T1/CEPT links• Line coding and decoding (duobinary, biphase, NRZ, RZ, AMI, CMI, B3ZS, and HDB3 codes)• Clock recovery

List of Equipment


1 Cables and Accessories - Digital Telecommunications _________________________________ 581540 (8949-10)


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1 Power Supply / Dual Audio Amplifier ______________________________________________ 581542 (9401-00)1 Dual Function Generator _________________________________________________________ 581549 (9402-10)1 Frequency Counter _____________________________________________________________ 581552 (9403-00)1 True RMS Voltmeter / Power Meter _______________________________________________ 581555 (9404-10)1 RF/Noise Generator ____________________________________________________________ 581561 (9406-00)2 Enclosure / Supply Regulator ____________________________________________________ 581592 (9420-00)1 Clock Generator ________________________________________________________________ 581593 (9421-00)1 Pseudo-Random Binary Sequence Generator ________________________________________ 581596 (9422-00)1 Bit Error Rate Indicator __________________________________________________________ 581599 (9423-00)1 Logic Analyzer _________________________________________________________________ 581602 (9424-00)1 DC Voltmeter / DC Source _______________________________________________________ 581605 (9425-00)2 Low Pass Audio Filter ___________________________________________________________ 581608 (9426-00)1 Synchronous Audio Generator ____________________________________________________ 581611 (9427-00)1 Signal Interruptor/Selector ______________________________________________________ 581614 (9428-00)1 Noise Measurement Filters _______________________________________________________ 581617 (9429-00)1 PAM/ASK Generator ____________________________________________________________ 581635 (9440-00)1 PAM/ASK Receiver _____________________________________________________________ 581638 (9441-00)1 PWM/PPM Generator ___________________________________________________________ 581641 (9442-00)1 PWM/PPM Receiver ____________________________________________________________ 581644 (9443-00)1 PCM Encoder __________________________________________________________________ 581647 (9444-00)1 PCM Decoder __________________________________________________________________ 581650 (9445-00)1 DPCM Encoder _________________________________________________________________ 581653 (9446-00)1 DPCM Decoder ________________________________________________________________ 581656 (9447-00)1 FSK Modem ___________________________________________________________________ 581659 (9449-00)1 BPSK Modulator _______________________________________________________________ 581662 (9450-00)1 BPSK Demodulator _____________________________________________________________ 581665 (9451-00)1 Delta/CVSD Encoder ____________________________________________________________ 581668 (9454-00)1 Delta/CVSD Decoder ___________________________________________________________ 581671 (9455-00)1 Storage Cabinet ________________________________________________________________ 581798 (9499-00)

List of Manuals

DescriptionManual number

Pulse Modulation and Sampling (Student Manual) ______________________________________ 580255 (27695-00)Digital Communications (Instructor Guide) _____________________________________________ 580259 (27695-10)Digital Modulation (Student Manual) _________________________________________________ 580264 (27696-00)Modems and Data Transmission (Student Manual) ______________________________________ 580272 (27697-00)

Table of Contents of the Manual(s)

Pulse Modulation and Sampling (Student Manual) (580255 (27695-00))• 1-1 Time Characteristics of Pulses• 1-2 Frequency Characteristics of Pulses• 1-3 Band-Limiting• 1-4 Noise and Signal Measurement• 2-1 PAM Signals


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• 2-2 Spectral Characteristics of PAM Signals• 2-3 Aliasing and Nyquist Rate• 2-4 Pre-filtering• 3-1 PAM Signal Demodulation• 3-2 Aliasing• 3-3 PAM Signal Transmission in the Presence of Noise• 4-1 PWM and PPM Signals• 4-2 The Effects of Noise and Band-Limiting on Pulse-Time Modulated Signals• 5-1 PWM and PPM Signal Demodulation• 5-2 The Effects of Noise and Band-Limiting on PWM / PPM Signal Demodulation• 6-1 Troubleshooting Techniques• 6-2 Troubleshooting the PAM Receiver• 6-3 Troubleshooting a PAM Communications System• 6-4 Troubleshooting the PWM / PPM Generator• 6-5 Troubleshooting the PWM / PPM Receiver• 6-6 Troubleshooting a PWM / PPM Communications System

Digital Modulation (Student Manual) (580264 (27696-00))• 1-1 Binary and Hexadecimal Numbers• 1-2 Analog-to-Digital Conversion• 1-3 Digital-to-Analog Conversion• 2-1 Distortion in PCM Systems• 2-2 Characteristics of Quantization Noise• 2-3 Quantization Noise Measurement• 3-1 Information Transmission with a PCM System• 3-2 Resistance of PCM to Noise and Distortion• 3-3 Effect of μ-Law Companding on the Performance of a PCM System• 3-4 Effect of A-Law Companding on the Performance of a PCM System• 4-1 Principles of a DPCM System• 4-2 Dynamic Operation of a DPCM System• 5-1 A Linear Delta Modulation (LDM) System• 5-2 An Adaptive Delta Modulation (ADM) System• 5-3 Signal-to-Noise Ratio in Delta Modulation• 6-1 Troubleshooting a PCM Communications Systems• 6-2 Troubleshooting a DPCM Communications Systems• 6-3 Troubleshooting a DM Communications Systems

Modems and Data Transmission (Student Manual) (580272 (27697-00))• 1-1 Pseudo-Random Binary Sequences• 1-2 Detection of NRZ Signals in Noise• 2-1 Generation and Reception of ASK Signals• 2-2 ASK Performance in Noise• 3-1 FSK Principles• 3-2 FSK Performance in Noise• 4-1 CCITT V.21 and Bell 103 Modems (300 baud)• 4-2 CCITT V.23 Mode 2 Modem (1200 baud)• 4-3 Bell 202 Modem (1200 baud)• 5-1 Generation and Demodulation of BPSK Signals


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• 5-2 BPSK Performance in Noise• 6-1 Troubleshooting an ASK Communications System• 6-2 Troubleshooting a FSK Modem• 6-3 Troubleshooting a BPSK Communication System

System SpecificationsParameter Value

Power Requirement 600 W

Physical Characteristics

Net Weight 113.7 kg (250.7 lb)

Space required per system 1.16 m² (12.5 ft²)

Digital Communications Add-On582008 (8085-30)

The Digital Communications Add-On is an add-on to the Analog Communications Training System, Model 8080-0 that enables users to perform the exercises in the Digital Communications courseware. Since both the Digital Communications and Analog Communications Training Systems share the same basic

equipment, this add-on is ideal to avoid any unnecessary duplication of equipment.

List of Equipment


1 Cables and Accessories - Digital Communications Add-On _____________________________ 581541 (8949-30)2 Enclosure / Supply Regulator ____________________________________________________ 581592 (9420-00)1 Clock Generator ________________________________________________________________ 581593 (9421-00)1 Pseudo-Random Binary Sequence Generator ________________________________________ 581596 (9422-00)1 Bit Error Rate Indicator __________________________________________________________ 581599 (9423-00)1 Logic Analyzer _________________________________________________________________ 581602 (9424-00)1 DC Voltmeter / DC Source _______________________________________________________ 581605 (9425-00)2 Low Pass Audio Filter ___________________________________________________________ 581608 (9426-00)1 Synchronous Audio Generator ____________________________________________________ 581611 (9427-00)1 Signal Interruptor/Selector ______________________________________________________ 581614 (9428-00)1 Noise Measurement Filters _______________________________________________________ 581617 (9429-00)1 PAM/ASK Generator ____________________________________________________________ 581635 (9440-00)1 PAM/ASK Receiver _____________________________________________________________ 581638 (9441-00)1 PWM/PPM Generator ___________________________________________________________ 581641 (9442-00)1 PWM/PPM Receiver ____________________________________________________________ 581644 (9443-00)1 PCM Encoder __________________________________________________________________ 581647 (9444-00)1 PCM Decoder __________________________________________________________________ 581650 (9445-00)1 DPCM Encoder _________________________________________________________________ 581653 (9446-00)1 DPCM Decoder ________________________________________________________________ 581656 (9447-00)1 FSK Modem ___________________________________________________________________ 581659 (9449-00)1 BPSK Modulator _______________________________________________________________ 581662 (9450-00)


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1 BPSK Demodulator _____________________________________________________________ 581665 (9451-00)1 Delta/CVSD Encoder ____________________________________________________________ 581668 (9454-00)1 Delta/CVSD Decoder ___________________________________________________________ 581671 (9455-00)1 Storage Cabinet ________________________________________________________________ 581798 (9499-00)

List of Manuals


Pulse Modulation and Sampling (Student Manual) ______________________________________ 580255 (27695-00)Digital Communications (Instructor Guide) _____________________________________________ 580259 (27695-10)Digital Modulation (Student Manual) _________________________________________________ 580264 (27696-00)Modems and Data Transmission (Student Manual) ______________________________________ 580272 (27697-00)


Pulse Modulation and Sampling (Student Manual) (580255 (27695-00))• 1-1 Time Characteristics of Pulses• 1-2 Frequency Characteristics of Pulses• 1-3 Band-Limiting• 1-4 Noise and Signal Measurement• 2-1 PAM Signals• 2-2 Spectral Characteristics of PAM Signals• 2-3 Aliasing and Nyquist Rate• 2-4 Pre-filtering• 3-1 PAM Signal Demodulation• 3-2 Aliasing• 3-3 PAM Signal Transmission in the Presence of Noise• 4-1 PWM and PPM Signals• 4-2 The Effects of Noise and Band-Limiting on Pulse-Time Modulated Signals• 5-1 PWM and PPM Signal Demodulation• 5-2 The Effects of Noise and Band-Limiting on PWM / PPM Signal Demodulation• 6-1 Troubleshooting Techniques• 6-2 Troubleshooting the PAM Receiver• 6-3 Troubleshooting a PAM Communications System• 6-4 Troubleshooting the PWM / PPM Generator• 6-5 Troubleshooting the PWM / PPM Receiver• 6-6 Troubleshooting a PWM / PPM Communications System

Digital Modulation (Student Manual) (580264 (27696-00))• 1-1 Binary and Hexadecimal Numbers• 1-2 Analog-to-Digital Conversion• 1-3 Digital-to-Analog Conversion• 2-1 Distortion in PCM Systems• 2-2 Characteristics of Quantization Noise• 2-3 Quantization Noise Measurement• 3-1 Information Transmission with a PCM System


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• 3-2 Resistance of PCM to Noise and Distortion• 3-3 Effect of μ-Law Companding on the Performance of a PCM System• 3-4 Effect of A-Law Companding on the Performance of a PCM System• 4-1 Principles of a DPCM System• 4-2 Dynamic Operation of a DPCM System• 5-1 A Linear Delta Modulation (LDM) System• 5-2 An Adaptive Delta Modulation (ADM) System• 5-3 Signal-to-Noise Ratio in Delta Modulation• 6-1 Troubleshooting a PCM Communications Systems• 6-2 Troubleshooting a DPCM Communications Systems• 6-3 Troubleshooting a DM Communications Systems

Modems and Data Transmission (Student Manual) (580272 (27697-00))• 1-1 Pseudo-Random Binary Sequences• 1-2 Detection of NRZ Signals in Noise• 2-1 Generation and Reception of ASK Signals• 2-2 ASK Performance in Noise• 3-1 FSK Principles• 3-2 FSK Performance in Noise• 4-1 CCITT V.21 and Bell 103 Modems (300 baud)• 4-2 CCITT V.23 Mode 2 Modem (1200 baud)• 4-3 Bell 202 Modem (1200 baud)• 5-1 Generation and Demodulation of BPSK Signals• 5-2 BPSK Performance in Noise• 6-1 Troubleshooting an ASK Communications System• 6-2 Troubleshooting a FSK Modem• 6-3 Troubleshooting a BPSK Communication System






Digital Communications Training System with LVDAM-COM582018 (8085-B0)

The Digital Communications Training System with LVDAM-COM provides modern and versatile equipment for measuring, observing, and analyzing signals in telecommunications systems. The LVDAM-COM system consists of a set of computer-based

instruments running on an IBM® -

compatible personal computer under the Microsoft® Windows operating environment. It can replace the Frequency Counter, True RMS Voltmeter / Power Meter, and Spectrum Analyzer. The LVDAM-COM system also includes a dual trace oscilloscope with a 40 MHz bandwidth.


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List of Equipment


1 Cables and Accessories - Digital Telecommunications _________________________________ 581540 (8949-10)1 Power Supply / Dual Audio Amplifier ______________________________________________ 581542 (9401-00)1 Dual Function Generator _________________________________________________________ 581549 (9402-10)1 RF/Noise Generator ____________________________________________________________ 581561 (9406-00)2 Enclosure / Supply Regulator ____________________________________________________ 581592 (9420-00)1 Clock Generator ________________________________________________________________ 581593 (9421-00)1 Pseudo-Random Binary Sequence Generator ________________________________________ 581596 (9422-00)1 Bit Error Rate Indicator __________________________________________________________ 581599 (9423-00)1 Logic Analyzer _________________________________________________________________ 581602 (9424-00)1 DC Voltmeter / DC Source _______________________________________________________ 581605 (9425-00)2 Low Pass Audio Filter ___________________________________________________________ 581608 (9426-00)1 Synchronous Audio Generator ____________________________________________________ 581611 (9427-00)1 Signal Interruptor/Selector ______________________________________________________ 581614 (9428-00)1 Noise Measurement Filters _______________________________________________________ 581617 (9429-00)1 PAM/ASK Generator ____________________________________________________________ 581635 (9440-00)1 PAM/ASK Receiver _____________________________________________________________ 581638 (9441-00)1 PWM/PPM Generator ___________________________________________________________ 581641 (9442-00)1 PWM/PPM Receiver ____________________________________________________________ 581644 (9443-00)1 PCM Encoder __________________________________________________________________ 581647 (9444-00)1 PCM Decoder __________________________________________________________________ 581650 (9445-00)1 DPCM Encoder _________________________________________________________________ 581653 (9446-00)1 DPCM Decoder ________________________________________________________________ 581656 (9447-00)1 FSK Modem ___________________________________________________________________ 581659 (9449-00)1 BPSK Modulator _______________________________________________________________ 581662 (9450-00)1 BPSK Demodulator _____________________________________________________________ 581665 (9451-00)1 Delta/CVSD Encoder ____________________________________________________________ 581668 (9454-00)1 Delta/CVSD Decoder ___________________________________________________________ 581671 (9455-00)1 Storage Cabinet ________________________________________________________________ 581798 (9499-00)

List of Manuals


Pulse Modulation and Sampling (Student Manual) ______________________________________ 580255 (27695-00)Digital Communications (Instructor Guide) _____________________________________________ 580259 (27695-10)Digital Modulation (Student Manual) _________________________________________________ 580264 (27696-00)Modems and Data Transmission (Student Manual) ______________________________________ 580272 (27697-00)Data Acquisition and Management System (User Guide) __________________________________ 584229 (31498-E0)Computer-Based Instruments (User Guide) ____________________________________________ 584393 (36220-E0)Virtual Test Equipment Interface (Instruction Manual) ____________________________________590054 (31559-D0)


Pulse Modulation and Sampling (Student Manual) (580255 (27695-00))• 1-1 Time Characteristics of Pulses• 1-2 Frequency Characteristics of Pulses


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• 1-3 Band-Limiting• 1-4 Noise and Signal Measurement• 2-1 PAM Signals• 2-2 Spectral Characteristics of PAM Signals• 2-3 Aliasing and Nyquist Rate• 2-4 Pre-filtering• 3-1 PAM Signal Demodulation• 3-2 Aliasing• 3-3 PAM Signal Transmission in the Presence of Noise• 4-1 PWM and PPM Signals• 4-2 The Effects of Noise and Band-Limiting on Pulse-Time Modulated Signals• 5-1 PWM and PPM Signal Demodulation• 5-2 The Effects of Noise and Band-Limiting on PWM / PPM Signal Demodulation• 6-1 Troubleshooting Techniques• 6-2 Troubleshooting the PAM Receiver• 6-3 Troubleshooting a PAM Communications System• 6-4 Troubleshooting the PWM / PPM Generator• 6-5 Troubleshooting the PWM / PPM Receiver• 6-6 Troubleshooting a PWM / PPM Communications System

Digital Modulation (Student Manual) (580264 (27696-00))• 1-1 Binary and Hexadecimal Numbers• 1-2 Analog-to-Digital Conversion• 1-3 Digital-to-Analog Conversion• 2-1 Distortion in PCM Systems• 2-2 Characteristics of Quantization Noise• 2-3 Quantization Noise Measurement• 3-1 Information Transmission with a PCM System• 3-2 Resistance of PCM to Noise and Distortion• 3-3 Effect of μ-Law Companding on the Performance of a PCM System• 3-4 Effect of A-Law Companding on the Performance of a PCM System• 4-1 Principles of a DPCM System• 4-2 Dynamic Operation of a DPCM System• 5-1 A Linear Delta Modulation (LDM) System• 5-2 An Adaptive Delta Modulation (ADM) System• 5-3 Signal-to-Noise Ratio in Delta Modulation• 6-1 Troubleshooting a PCM Communications Systems• 6-2 Troubleshooting a DPCM Communications Systems• 6-3 Troubleshooting a DM Communications Systems

Modems and Data Transmission (Student Manual) (580272 (27697-00))• 1-1 Pseudo-Random Binary Sequences• 1-2 Detection of NRZ Signals in Noise• 2-1 Generation and Reception of ASK Signals• 2-2 ASK Performance in Noise• 3-1 FSK Principles• 3-2 FSK Performance in Noise



1 Refer to the Computer Requirements in the System Specifications section of this datasheet if the computer is to be provided by the end-user.

• 4-1 CCITT V.21 and Bell 103 Modems (300 baud)• 4-2 CCITT V.23 Mode 2 Modem (1200 baud)• 4-3 Bell 202 Modem (1200 baud)• 5-1 Generation and Demodulation of BPSK Signals• 5-2 BPSK Performance in Noise• 6-1 Troubleshooting an ASK Communications System• 6-2 Troubleshooting a FSK Modem• 6-3 Troubleshooting a BPSK Communication System

Computer-Based Instruments (User Guide) (584393 (36220-E0))• 1 Familiarization with the True RMS Voltmeter and Frequency Counter• 2 Familiarization with the Oscilloscope• 3 Familiarization with the Spectrum Analyzer

Additional Equipment Required to Perform the Exercises


1 Personal Computer _____________________________________________________________ 579785 (8990-00)






Equipment Description

Cables and Accessories - Digital Telecommunications 581540 (8949-10)

The Cables and Accessories - Digital Telecommunications set contains the various cables and accessories required to perform the exercises in the courseware. The accessories package contains the following parts: three different lengths of coaxial

cables terminated with BNC connectors , whip, pigtail, and folded dipole antennas, BNC T-connectors, resistive loads with BNC connectors, headset. These accessories come in a convenient plastic storage case.

SpecificationsParameter Value

Cables

Coaxial BNC/BNC 30 cm (14), 75 cm (6), 120 cm (2)

Multi-Conductor D9/D9 40 cm (5), 70 cm (2)

Resistive Loads

BNC Terminated 50 Ω (1), 620 Ω (1)

Accessories

BNC T-Connector 6

Stereo Headset 1

1



Cables and Accessories - Digital Communications Add-On 581541 (8949-30)The Cables and Accessories - Digital Communications Add-On set contains the various cables and accessories required to perform the exercises in the courseware. The accessories package contains the following parts: three different lengths of coaxial cables terminated with BNC connectors, whip, pigtail, and folded dipole antennas, BNC T-connectors, resistive loads with BNC connectors, headset. These accessories come in a convenient plastic storage case.


Cables

Coaxial BNC/BNC 30 cm (8)

Multi-Conductor D9/D9 40 cm (5), 70 cm (2)

Resistive Loads

BNC Terminated 620 Ω (1)

Accessories

BNC T-Connector 2

Power Supply / Dual Audio Amplifier 581542 (9401-00)

The Power Supply / Dual Audio Amplifier module forms the physical base for the analog and digital communications training systems, and can be used in several other training

systems. It is double-width to accommodate two instructional modules or two instrument modules in a side-by-side configuration. A two-channel audio amplifier with headphone jacks and speakers accommodates FM stereo and narrowband FM and AM receiver outputs.

The power supply distributes power to the complete system and provides three regulated dc voltage outputs (15 V – 0.5 A; -15 V – 0.5 A; +5 V – 1 A) on the faceplate. Also unregulated voltages are distributed to the system modules through a connector located on each module. These unregulated voltages are regulated within each module to provide the required voltages. Each regulated supply has an LED indicator that shuts off if the supply is overloaded due to equipment malfunction or if a faulty power connection is made to external equipment.


Power Requirement

Current 3.5 A

Service Installation Standard single-phase ac outlet

Power Outputs

Unregulated Power Bus ±25 V typ. – 3 A max; -25 V typ. – 3 A max.; +11 V typ. – 5 A max.

Regulated Front Panel ±15 V – 0.5 A; + 5 V – 1 A

Dual Audio Amplifier Rating

Bandwidth 50 Hz to 15 kHz

Input Impedance 10 kΩ

Nominal Output Power 250 mW

Sensitivity (at nominal output power) 140 mW

Output Impedance (intermediate outputs) 1 kΩ

Maximum Output Level (open-circuit) 20 V p-p

Protection

AC Line Input Circuit breaker

DC Regulated Outputs Foldback current-limiting

DC Unregulated Outputs Circuit breaker



Parameter Value


Dimensions (H x W x D) 104 x 687 x 305 mm (4.1 x 27 x 12 in)


Dual Function Generator 581549 (9402-10)

The Dual Function Generator consists of two independent function generators (A and B), each capable of generating a sine-wave signal, a square-wave signal, a triangular-wave signal, a sawtooth-wave signal, and a pulse signal with variable pulse-width. The signal frequency can be varied from 10 Hz to 100 kHz through four

ranges. A digital display is pushbutton-selectable between generators A and B to monitor the frequency of each generator. Each generator output signal level is continuously variable and may be attenuated by push button-selected switch attenuators. TTL output signals are provided to synchronize external equipment, such as an oscilloscope. Generator A may be frequency-modulated by a signal from generator B or from an external source.

The module is fully protected against short circuits and misconnections. Students use the instruments to make measurements in laboratory experiments performed on AM, FM, and digital communications systems.


Power Requirement ±25 V typ. – 3 A max; -25 V typ. – 3 A max.; +11 V typ. – 5 A max.

Generators (A & B) Rating

Waveforms Sine, triangle, square, sawtooth, or pulse

Pulse Duty Cycle 10 to 90 %

Frequency Ranges 10-100 Hz, 100-1000 Hz, 1-10 kHz, 10-100 kHz

Frequency Display (switchable between A & B) 4 digits

Output Impedance 50 Ω

Output Level (open circuit) 10 mV p-p to 10 V p-p

Attenuator 0, 20, or 40 dB

Synchronization Outputs One for each channel (SYNC/TTL)

Frequency Modulation (Channel A only)

Input Impedance 100 kΩ

Maximum Frequency Deviation 50 % of each side of the rest frequency

Input Level for Maximum Deviation 10 V p-p


Dimensions (H x W x D) 162 x 330 x 300 mm (6.4 x 13 x 11.8 in)


Frequency Counter 581552 (9403-00)

The Frequency Counter is a direct-counting frequency counter with an 8-digit display. The frequency counter has three functions: it determines the frequency of the input signal and displays the frequency in Hz, kHz, or MHz, it determines the period of the



input signal and displays the period in s or ms, and it works as an event counter when the counter function is selected. The frequency/period resolution is switch-selectable from 0.1 to 100 Hz (0.1 to 100 ns). As an event counter, each negative-going transition of the input signal adds one to the cumulative count displayed. The input signal may be attenuated by a switch attenuator.



Power Requirement +25 V – 425 mA; -25 V – 325 mA

Rating

Input Frequency Range 10 Hz - 10 MHz, 10 MHz - 200 MHz

Input Period Range 0.1 s – 4 µs (10 Hz-2.5 MHz)

Count Range 1 - 99 999 999

Input Impedance 1 MΩSensitivity (Sine Wave RMS Value) 10 Hz - 100 MHz: 25 mV; 100 MHz-200 MHz: 60 mV

Attenuator 0, 20 or 40 dB

Resolution 0.1, 1, 10, 100 Hz (ns)

Frequency Display 8 digits



Net Weight 3.2 kg (7 lb)

True RMS Voltmeter / Power Meter 581555 (9404-10)

The True-RMS Voltmeter / Power Meter is a dual function instrument used to measure RMS voltage or signal power in communications systems. Voltage and power can be measured through four ranges on a 3½ digit panel display. The function is

switch-selectable on the front panel. The input signal frequency range is 20 Hz to 12 MHz. An automatic zero-adjust function readjusts the meter’s zero at regular time intervals. This feature provides precise measurements over a wide range of temperature.



Power Requirement +25 V – 125 mA; +11 V – 350 mA; -25 V – 75 mA

Rating

Measurement Bandwidth 20 Hz to 12 MHz

Input Impedance 1 MΩ

Voltage Ranges 10 mV, 100 mV, 1 V, 10 V

Power Ranges -27, -7, +13, +33, (50 Ω input)

Accuracy (10 mV and 100 mV Ranges) ±3 % (20 Hz to 12 MHz)

Accuracy (1 V and 10 V Ranges) ±5 % (20 Hz to 12 MHz)






RF/Noise Generator 581561 (9406-00)

The RF/Noise Generator contains two independent generators capable of generating a tone signal in the frequency range from 100 kHz to 32 MHz and a "white" noise signal in selected frequency bands from 0 to 11.2 MHz. The radio frequency (RF) generator produces a signal output in five frequency ranges to cover the frequencies in the analog

communications system. This generator has FM and AM capabilities.

The noise generator provides white noise in five independent frequency bands. The noise output may be used for measuring the frequency response of filters or the signal-to-noise ratio in any part of the system.



RF Generator Rating

Frequency Ranges 100-320 kHz, 0.32-1 MHz, 1-3 MHz, 3-10 MHz, 10-32 MHz

Output Voltage (across 50 Ω) 100 mV p-p

Output impedance 50 Ω

SYNC Output Level 1.5 V p-p min.

Amplitude Modulation Input Level 1 V p-p

Amplitude Modulation Input Impedance 10 kΩ

Frequency Modulation Input Level 1 V p-p

Frequency Modulation Input Impedance 10 kΩ

Noise Generator Rating

Frequency Ranges Audio: 2 Hz - 20 kHz

Audio/RF: 0 Hz - 2 MHz

AM IF Noise: 435-475 kHz

SSB RF Noise: 3.6-4.2 MHz

FM IF Noise: 10.2-11.2 MHz

Output Voltage (across 50 Ω) 0.5 V rms




Net Weight 4 kg (8.8 lb)



Enclosure / Supply Regulator 581592 (9420-00)

The Enclosure / Supply Regulator provides enough regulated power to supply four digital communications modules. It converts unregulated dc voltages from the Power Supply / Dual Audio Amplifier, Model 9401, into four regulated dc voltages accessed via backplane connectors. Built-in guides facilitate the insertion of modules into the enclosure, while a thumbscrew fastener secures each module in the

enclosure. Each module is automatically powered through the backplane connectors installed inside the enclosure.


Power Requirements Connection to the Power Supply / Dual Audio Amplifier, Model 9401

DC Regulated Outputs

DC Regulated Outputs +15 V – 1 A

-15 V – 1 A

+5 V – 1 A

-5 V – 0.5 A


Dimensions (H x W x D) 215 x 675 x 320 mm (8.5 x 26.6 x 12.6 in)


Clock Generator 581593 (9421-00)

The Clock Generator provides a series of synchronized clock signals required for the clocking functions of the digital communications system. The module consists of a master clock driving a 10^n-frequency divider, which in turn drives eight divide-by-two cascade-connected frequency dividers. Access

to the output signals of each section is achieved through BNC connectors. In addition, a multi-pin connector provides the output signals from each of the divide-by-two frequency dividers. All frequency divider output signals have a 50% duty cycle.

One of the following four master clocks can be selected through push buttons:

• variable frequency clock (1-10 MHz)• crystal-controlled fixed-frequency clock (10 MHz)• external clock• manual clock (activated through a push-button switch)



The frequency-division ratio of the 10^n-frequency divider is determined using a push button that selects an integer power n from 0 to 7. An LED display indicates the chosen frequency-division ratio.

The Clock Generator can be stacked on top of the Power Supply / Dual Audio Amplifier, Model 9401, the Enclosure / Supply Regulator, Model 9420, the FSK Modem, Model 9449, or on top of any module of the Analog Communications Training System. Power is distributed through the self-aligning multi-pin connectors located on the top and bottom of the modules.



External Clock Input

Maximal Frequency 10 MHz

Clock Outputs

Clock Outputs A (Master Clock)

Complement of A

B (Master Clock/[10^n]) (n=0 to 7, switch selectable)

Complement of B

B/[2^n] (n=1 to 8)

Composite Clock (all eight B/[2^n] clock outputs on D-connector)

Output Impedance 50 Ω (all BNC outputs)



3.3 kg (7.3 lb) 3.3 kg (7.3 lb)

Pseudo-Random Binary Sequence Generator 581596 (9422-00)

The Pseudo-Random Binary Sequence (PRBS) Generator designed to be used with the Bit Error Rate Indicator, Model 9423, to measure the reliability (error rate) of different digital transmission systems.

Using an external clock, the PRBS Generator produces a pseudo-random sequence of bits. The bit rate can be varied from 100 bps to 5.44 Mbps. The length of the pseudo-random

sequence of bits is selected through a switch and is indicated on the front panel of the module. Sixteen sequence lengths are available between 1 and 65,535 bits. One of the sequences is 511 bits long, thus meeting with recommendation V.52 of the CCITT. The generated pseudo-random bit sequence recurs indefinitely. The generator produces a synchronization signal for oscilloscope observation of the PRBS.

A delayed PRBS is required when assessing the reliability of a digital transmission system. The delay of the PRBS must match that caused by the digital transmission system under test. For this purpose, the PRBS can be delayed by a fraction of a bit (fraction of a clock period) or by a whole number of bits (whole clock periods) using controls located in the DELAY block of the module.


Power Requirements Connection to the Enclosure / Supply Regulator, Model 9420

Clock Input



Parameter Value

Frequency 5.44 MHz maximum

PRBS PRBS

Delayed PRBS (0 to 45 clock periods) Delayed PRBS (0 to 45 clock periods)

Delayed Clock Delayed Clock

Sync. Sync.

PRBS Length 1 bit to [2^16]-1 (= 65,535 bits)



Net Weight 1 kg (2.2 lb)

Bit Error Rate Indicator 581599 (9423-00)

The Bit Error Rate Indicator is designed to be used with the Pseudo- Random Binary Sequence Generator, Model 9422, to measure the transmission error rate on a bit stream within a communication system, in order to assess the reliability of the communication path.

The module compares two data streams and counts, for a specific

period of time, the number of non-identical bits. Three test durations can be selected: 1 s, 10 s or 100 s. Error rates can be measured within a range of 0.01 error per second to 9999 errors per second.

At the end of each test period, the error rate appears in errors per second on a 4-digit display. The display will blink in case of overflow. The counting cycle is automatically reset when another test duration is selected. Each new reading can be announced by a tone, which is useful for long test periods. This feature can be disabled at any time. The tone generator cannot be used for a test period of 1 s.



Clock Input


Auxiliary Output


Display 4 digits






Logic Analyzer 581602 (9424-00)

The Logic Analyzer is designed to observe successive bytes (8-bit words) on any 8-bit bus. The Logic Analyzer operation is divided into two distinct parts: data acquisition and data display.

The data acquisition is controlled using a push button and can be triggered by an internal or external signal. During data acquisition

incoming, 8-bit words are stored in the Logic Analyzer's memory until full. The memory capacity is 2048 8-bit words. A clock signal is required to carry out the data acquisition. The data in memory is stored until a new data acquisition is carried out or until the power is turned off.

Once data acquisition is completed, the Logic Analyzer automatically proceeds with data display. The Logic Analyzer produces X-Y signals which allow observation on an oscilloscope screen of a group of 8-bit words stored in its memory. Each group or memory segment contains sixteen 8-bit words. The memory segment observed is selected through the use of push buttons. The number of the selected segment can be displayed on a 2-digit hexadecimal display. This display can also be used to obtain the hexadecimal representation of the 8-bit word present at the data input of the Logic Analyzer. The display on the oscilloscope screen consists of 8 horizontal traces. Each of these traces represent 1 bit of the 8-bit words. The lower trace represents the least significant bit (LSB) whereas the upper trace represents the most significant bit (MSB).



Clock Input

Frequency 1 MHz maximum

Data Input 8-bit parallel

Memory 2K x 8-bit

X and Y Outputs 8-level multiple signal to oscilloscope

Hexadecimal Display 2-digit

Indicators

Indicators Acquiring data

Trigger Ready Trigger ready






DC Voltmeter / DC Source 581605 (9425-00)

The DC Voltmeter / DC Source combines a high-impedance digital dc voltmeter and a low-current dc source. The dc Source is designed to supply a user-adjustable reference voltage. The digital display of the dc voltmeter provides accurate voltage readings. The module is used mainly in the study of analog-to-digital conversions

and of digital-to-analog conversions.

The dc source voltage is adjustable through a ten turn potentiometer. Its value can be read from the voltage display by pressing a push button on the front panel of the module.

The dc voltmeter can be used on one of two ranges selected through a push button. The measured voltage is indicated on a 3½ digit display. The high input impedance of the dc voltmeter allows for a precise reading without disturbing the circuits being tested.



DC Voltmeter

Input Impedance 1 MΩ

Ranges ±2 V, ±20 V

Resolution 1 mV on ±2 V range

10 mV on ±20 V range

DC Source Output -2 V to +2 V, 25 mA maximum

Display 3½ digit




Low Pass Audio Filter 581608 (9426-00)

The Low Pass Audio Filter provides a second- or fourth-order filter with variable cutoff frequency. It is used before sampling and after decoding in digital communications systems to provide band-limited signals. The module is normally ac coupled, but dc coupling may be selected so that a digital signal can be band-limited for noise measurement purposes.



Audio Input

Voltage 2 V p-p input



Parameter Value

Impedance 600 Ω

Audio Output

Voltage 2 V p-p with 2 V p-p input (gain control at CAL position)

Impedance 600 Ω

Cutoff Frequency (3dB) 300 Hz to 8 kHz




Synchronous Audio Generator 581611 (9427-00)

The Synchronous Audio Generator provides a triangle-wave audio signal that is synchronized to the system clock and enables PAM, PWM, PPM, and PCM signals throughout the system to be observed easily. The audio signal is derived from the clock input signal using a frequency divider and an integrator. An automatic gain control circuit ensures a stable output

level as frequency is varied.



Clock Input

Maximal Frequency 500 kHz

Frequency Division 10 (3 kHz to 50 kHz)

100 (30 kHz to 500 kHz)

Audio Output

Nominal Voltage 2 V p-p (gain control at CAL position)

Maximal Voltage 10 V p-p

Impedance 600 Ω




Signal Interruptor/Selector 581614 (9428-00)

The Signal Interruptor/Selector performs two functions in the system. It allows selective interruption of one or more lines on an 8-bit data bus to demonstrate the effect of losing bits in data transmission. The relative importance of each bit can also be demonstrated, e.g., the effect of interrupting the MSB line compared with interrupting the LSB line.



Furthermore, the Signal Interruptor/Selector is an interface for the test points, which are accessible via D-type connectors on the front panels of the instructional modules. Any two test points can be selected independently and are made available at two BNC connectors on the front panel of the Signal Interruptor/Selector, for observation on a dual channel oscilloscope. LEDs indicate which signal has been selected.



Inputs 8-bit parallel

Outputs

Outputs 8-bit parallel

2 x Signal Outputs (BNC)




Noise Measurement Filters 581617 (9429-00)

The Noise Measurement Filters measure the noise content of various signals in the system by separating noise from signals using filtering techniques. They can also be used to measure quantization and intermodulation noise, as well as noise on voice channels.

The module contains a selectable frequency low-pass filter, a band-pass

filter, and a notch filter. The low-pass filter simulates transmission channels of different bandwidths. It is preceded by a summing amplifier allowing the addition of a noise signal to simulate a "noisy" transmission channel. The notch filter and the band-pass filter have the same center frequency in order to measure signal-to-noise (S/N) ratios. The band-pass filter can be used for cleaning up a signal or for Gaussian noise generation.



All Inputs

Voltage 2 V p-p

Impedance 600 Ω

All Outputs

Voltage 2 V p-p

Impedance 600 Ω

Band-Pass Filter

Center Frequency 100 Hz, 300 Hz, 1 kHz

Notch Filter

Center Frequency 100 Hz, 300 Hz, 1 kHz

Low Pass Filters

Cutoff Frequency 20, 40, 80, 160 kHz






PAM/ASK Generator 581635 (9440-00)

The PAM/ASK Generator converts analog input signals to Pulse Amplitude Modulated (PAM) output signals or digital data to Amplitude Shift Keyed (ASK) output signals.

In PAM, an analog input signal is sampled using either natural or flat-top sampling, and a pulse with a height proportional to the input signal amplitude is generated at each sample

point. In ASK, a tone is output for a "1" and no tone is will be the output for a "0" at the input. PAM and ASK are not true digital signals, since both convey information as modified analog signals rather than as a digital code.

Using the PAM/ASK Generator, students gain an understanding of the principles of PAM and ASK generation. The relationship between the sampling rate and highest frequency present in the modulating signal, and the effects of bandwidth and pulse duration are also investigated.



Sampling Modes Natural, Flat Top

Audio/Carrier Input

Voltage 2 V p-p

Impedance 600 Ω


Clock/Data Input


PAM / ASK Output

Nominal Voltage 2 V p-p with 2 V p-p input (gain control at CAL position)


Impedance 600 Ω

Maximal ASK Data Rate 9600 Bd

Fault-Insertion Switches 8

Test Points 6






PAM/ASK Receiver 581638 (9441-00)

The PAM/ASK Receiver demodulates PAM or ASK signals from the PAM/ASK Generator to recover the original analog signals or data. Using the PAM/ASK Receiver, students become familiar with techniques used in the demodulation of PAM and ASK signals.



PAM / ASK Inputs

Voltage 2 V p-p

Impedance 600 Ω

Maximal ASK Data Rate 1200 Bd

Audio Output

Nominal Voltage 2 V p-p with 2 V p-p input (gain control at CAL position)


Impedance 600 Ω

Frequency 3.4 kHz

Data Output

Voltage TTL


Test Points 7




PWM/PPM Generator 581641 (9442-00)

The PWM/PPM Generator converts analog input signals to Pulse Width Modulated (PWM) or Pulse Position Modulated (PPM) output signals.

In PWM, an analog input signal is sampled, and a pulse whose width (duration) is proportional to the input signal amplitude is generated at each sample point. In PPM, an analog input signal is sampled an a pulse whose

position is proportional to the input signal amplitude is generated at each sample point. Both PWM and PPM signals are of constant height (amplitude), and the pulses in PPM signals are of constant width. Although PWM and PPM are more complex forms of message processing than PAM, they still are not considered true digital signals.

Using the PWM/PPM Generator, students can gain an understanding of how PWM and PPM signals are generated. The noise resistance characteristics of PWM/PPM signals can be studied also.





Audio Input

Voltage 2 V p-p

Impedance 600 Ω

Frequency Range 300 Hz to 5 kHz

Ramp Input

Voltage 2.2 V p-p

Impedance 600 Ω


PWM / PPM Outputs

Voltage 5 V TTL, (gain control at CAL position) 0-5 V variable

PPM Pulse Duration 3 µS to 1 mS


Test Points 6




PWM/PPM Receiver 581644 (9443-00)

The PWM/PPM Receiver is part of the 13 digital communications instructional modules that offer superior training in Telecommunications technology. It demodulates PWM or PPM signals from the PWM/PPM Generator to reconstruct the original analog signal. Using the PWM/PPM Receiver,

students become familiar with the PWM / PPM decoding process. The relationship between PWM and PPM is easily demonstrated.



PWM / PPM Inputs

Voltage TTL

Clock Input

Voltage TTL


Audio Output



Impedance 600 Ω

Frequency Range 300 Hz to 3.4 kHz


Test Points 6






PCM Encoder 581647 (9444-00)

The PCM Encoder converts an analog input signal to a digitally-coded output signal (pulse to PAM, PWM, and PPM), since the PCM output is in binary code.

In PCM, an analog input signal is sampled and an 8-bit code is generated representing the input signal amplitude at each sample point. A bar graph indicator for the test bus shows the logic states of the 8-bit A/D converter output. Both parallel and

serial PCM outputs are provided for experimental work.

Using the PCM Encoder, students become familiar with the basics of A/D conversion and PCM signal generation. Other important concepts, such as quantization error and volume compression are studied as well.



Audio Input

Voltage 2 V p-p

Impedance 600 Ω


Clock Input


Outputs Serial-bit parallel end of conversion (A/D converter)

Output Voltage TTL

Compression Modes

Compression Modes 4 Bell µ-type laws

3 CCIT A-type laws

Direct (no compression)


Test Bus 1




PCM Decoder 581650 (9445-00)

The PCM Decoder is used to demodulate a serial PCM signal generated by the PCM Encoder, or a parallel PCM signal generated by either the PCM Encoder or the DPCM Decoder, and to recover the original analog signal. A bar graph indicator for the test bus shows the logic states of the 8-bit D/A converter input.



Using the PCM Decoder, students gain familiarity with PCM decoding and D/A conversion processes. The effects of compression and expansion on weak and strong signals can be investigated also.



PCM Input Voltage TTL

Input Codes

Input Codes Offset Binary

Sign Offset

µ2-Type Expansion

A1-Type Expansion

Audio Output



Impedance 600 Ω



Test Bus 1




DPCM Encoder 581653 (9446-00)

The DPCM Encoder accepts parallel PCM signals from the PCM Encoder and produces a parallel Differential Pulse Code Modulated (DPCM) signal.

A DPCM signal results when consecutive PCM signals are subtracted, so that only the difference between the signals is transmitted. DPCM offers advantages over PCM for voice signals, such as lower sampling rates and the ability to multiplex more

channels on the same transmission link. DPCM requires fewer bits to encode the analog information and suffers less from noise degradation than PCM.

Using the DPCM Encoder, students gain an understanding of the processes used to obtain DPCM signals, the differences between PCM and DPCM, and the advantages and disadvantages of each.



Inputs 8-bit parallel PCM end of conversion (from PCM Encoder)

Outputs Less than 8-bit parallel DPCM

Input/Output

Voltages TTL


Test Busses 6






DPCM Decoder 581656 (9447-00)

The DPCM Decoder is converts the less than 8-bit parallel DPCM signals from the DPCM Decoder to an 8-bit PCM signal. This PCM signal is then fed to the parallel input of the PCM Decoder to recover the original analog signal.

Using the DPCM Decoder, students gain an understanding of the more complex processes involved in DPCM decoding and the effects of noise on DPCM transmissions.



Inputs Less than 8-bit parallel DPCM end of conversion (from PCM Encoder)

Output 8-bit parallel PCM

Input/Output

Voltages TTL


Test Busses 5




FSK Modem 581659 (9449-00)

The FSK Modem converts TTL of RS-232C data to Frequency Shift Keyed (FSK) audio signals which are compatible with a telephone line. The FSK Modem also converts FSK audio signals to TTL or RS-232C data. Full-duplex and half-duplex operation is

possible. FSK is the most popular method of low- and medium-speed data transmission.

Using the FSK Modem, students gain an understanding of FSK generation, logic compatibility, data transmission speeds, and standards used in FSK communications.



Analog Input/Output 2- or 4-wire through 600 Ω balancing transformer

Digital Input/Output TTL or RS-232C data

Modes of Operation

Modes of Operation Bell 103

Originate/Answer, full-duplex, half-duplex (2- or 4-wire)

Bell 202

Bell 202 Equalized (V.21 ... o/A, F/D; V.23 .. Mode 2; V.23 ... Mode 2

Equalized half-duplex



Parameter Value

Digital and analog loopback


Test Points 26




BPSK Modulator 581662 (9450-00)

The BPSK Modulator converts TTL data to Binary Phase Shift Keyed (BPSK) signals. BPSK is used extensively in high-speed data transmission. Using the BPSK Modulator, students gain an understanding of the BPSK modulation process, as well as data rate limitations of a BPSK system.



Data Input

Voltage TTL

Maximal Data Rate 9600 Bd

Clock Input

Voltage TTL


Outputs Phase Modulator BPSK

BPSK Output


Impedance 600 Ω


Test Points 8




BPSK Demodulator 581665 (9451-00)

The BPSK Demodulator demodulates the BPSK signals from the BPSK Modulator and recovers the original data signal. The module employs demodulation techniques with the Costas Loop. Using the BPSK Demodulator, students gain an understanding of BPSK demodulation techniques, as well as phase ambiguity and bit error rate

measurement.

Specifications



Parameter Value


BPSK Input

Voltage 2 V p-p

Impedance 600 Ω

Data Output

Voltage TTL

Maximal Data Rate 2400 Bd


Test Points 8




Delta/CVSD Encoder 581668 (9454-00)

The Delta/CVSD Encoder converts audio input signals to Delta Modulated or Continuously Variable Slope Delta (CVSD) modulated output signals.

Delta Modulation uses a more direct encoding process than PCM. In Delta Modulation, an analog signal is sampled and either a "1" or a "0" is transmitted at each sample point, depending on whether the sample size

is larger or smaller than the previous sample size. The use of CVSD considerably increases the dynamic range of the audio input signals that can be used.

Using the Delta/CVSD Encoder, students gain an understanding of the Delta Modulation encoding process. The difference between Delta Modulation and CVSD can be studied, together with their performance at different rates.



Audio Input

Voltage 2 V p-p

Impedance 600 Ω


Clock Input

Voltage TTL


Delta / CVSD Output

Voltage TTL


Test Points 7






Delta/CVSD Decoder 581671 (9455-00)

The Delta/CVSD Decoder is demodulates the Delta or CVSD modulated signal from the Delta / CVSD Generator and recovers the original analog signal. Using the Delta/CVSD Decoder, students gain an understanding of Delta / CVSD demodulation techniques. Distortion of the modulated signal due to slope

overload or weak and noisy signals can be studied, as well as the effects of noise on the transmitted signals.



Delta / CVSD Input

Voltage TTL

Clock Input

Voltage TTL


Audio Output

Voltage 2 V p-p

Impedance 600 Ω



Test Points 6




Storage Cabinet 581798 (9499-00)

The Storage Cabinet contains six shelves and can hold 24 modules from the Digital Communications Training Systems, Series 8085. The Storage Cabinet requires assembly. A diagram is provided to facilitate assembly.

Specifications



Parameter Value

Capacity 24 modules from the Digital Communications Training Systems, Series 8085

Material Hard wood


Dimensions (H x W x D) TBE

Net Weight TBE

Optional Equipment Description

Dual Trace Oscilloscope (Optional) 580849 (797-20)

The Dual Trace Oscilloscope is an economical and highly reliable solid-state instrument, ideal for general-purpose use in laboratory and training applications. Students can measure phase difference between waveforms using the X-Y operation mode, and video signals can be measured quickly with the special TV sync separation circuit. The Dual Trace Oscilloscope

includes CH 1, CH 2, CHOP, and ALT display modes. An operating instruction manual, one fuse, one line cord, and two low-capacitance probes are provided with the oscilloscope.

Features & Benefits

• 15 cm (6 inch) width, high luminance CRT with internal graticule, 8 x 10 divisions• Wide dynamic range even at high frequencies of −3 dB• Fast rise time with low overshoot• Flat frequency response up to half of −3 dB frequency• Alternate and chopping display• Polarity inversion and algebraic sum of CH1 and CH2• Maximum sweep rates of 20 ns/div.• Variable scale illumination• Delayed sweep function with minimum delay time jitter of 1/20,000 or less• Jitterless and superb trigger sensitivity• TV sync separation and hold-off circuit useful for video signal observation• Brightness modulation available with Z-axis input• Low drift with compensation circuitry• Signal delay with delay line useful for observation of signal leading edge• X-Y phase difference measurement up to 50 kHz


Power Requirements

Current 0.4 A


CRT Display

Type 15.24 cm (6 in) rectangular, internal graticule, scale illumination

Effective Area 8 x 10 div (1 div = 1 cm)

Acceleration Potential 12 kV

Vertical Deflection



Parameter Value

Sensitivity 5 mV/div to 5 V/div in 10 calibrated steps ±3%

1 mV/div to 1 V/div ±5% when using x5 magnifier

Uncalibrated continuous control between steps 1:<2.5

Bandwidth DC to 40 MHz (-3 dB); dc to 7 MHz (-3 dB) when using x5 magnifier

Rise Time Less than 8.8 ns

Maximum Input 300 V (dc + ac peak) or 500 V p-p ac at 1 kHz or less

Input Coupling AC, GND, DC

Input Impedance 1 meg in parallel with 25 pF

Operating Modes CH1, CH2 (INVERT), ADD, DUAL (CHOP: Time/div sw 0.2 s - 5 ms; ALT: Time/div sw 2 ms - 0.2µs)

X-Y Operation CH1: X-axis, CH2: Y-axis

Horizontal Deflection

Display A, A int B, B, B triggered, X-Y

Time Base A 0.2 µs/div to 0.2 s/div in 19 calibrated steps ±3% uncalibrated continuous control between steps at least 1:<2.5

Time Base B 0.2 µs/div to 20 µs/div in 7 calibrated steps ±3%

Trigger

Modes Auto, Norm, TV-V, TV-H

Coupling AC

Sources CH 1, CH 2, LINE, EXT

Sensitivity (Internal Source) 0.5 div (20 Hz to 2 MHz), 1.5 div (2 MHz to 40 MHz)

Sensitivity (External Source) 200 mV (20 Hz to 2 MHz), 800 mV (2 MHz to 20 MHz)

Slope + or -

TV Sync Polarity: TV (-)

Calibrator 1 kHz, square wave, 0.5 ±3%, duty cycle: 50%

Accessories Power cable, fuse, operation manual, 2 probes




Personal Computer (Optional) 579785 (8990-00)

The Personal Computer consists of a desktop computer running under

Windows® 10. A monitor, keyboard, and mouse are included.


Power Requirements

Current 2 A




FM/PM Receiver (Optional) 581589 (9415-10)

The FM/PM Receiver offers training in multiplex and wideband FM (covering commercial broadcast techniques), narrowband FM (widely used in commercial and military communications systems), and PM reception. PM reception is used in such applications as satellite

communications, data communications, over narrowband communications systems, telephone lines, microwave communications lines and links.

When the FM/PM Receiver is connected with the Direct FM Multiplex Generator, a complete commercial FM system is established. Students can readily see the effects of stereo signal generation, multiplexing techniques, and modulation. When the FM/PM Receiver is connected to the Indirect FM/PM Generator, a narrowband FM communications link is established, allowing the student to explore the generation and reception of narrowband FM and PM signals.

RF inputs to the receiver are between 88 and 108 MHz for stereo and wideband FM, and 10.7 MHz for narrowband FM and PM. A demodulated audio signal is available at the NBFM audio output when a signal is injected at the RF input. When the output of the crystal discriminator is connected to the input of the integrator, a demodulated audio signal is available at the PM audio output.

The WBFM section is equipped with two 50 Ω RF inputs, a balanced 300 Ω RF input for an external antenna connection, and an RF tuning knob which allows tuning across the 88- to 108-MHz band.

A 3-LED tuning indicator and a 10-LED bar graph display (indicating received signal level) facilitate accurate tuning. The presence of the 19 kHz pilot signal illuminates an LED also. A 2½ digit display can show the frequency deviation of the received WBFM or NBFM signals. These meters are often used on modern communications receivers.

Receiver outputs for FM left and right stereophonic channels, monophonic FM, NBFM, and PM are provided, as well as an SCA channel audio output, often used for background music programming.


Power Requirements

Power Requirements +25 V dc - 275 mA

+11 V dc - 200 mA

-25 V dc - 150 mA

WBFM Section

Input Impedance 2 inputs at 50 Ω, 1 input at 300 Ω (balanced)

50 Ω Input Sensitivity 55 µV (typical for both inputs for 10 dB S/N at baseband output)

300 kΩ Input Sensitivity 15 µV ( typical for 10 dB S/N at baseband output)

AUX IF Input Impedance 50 Ω

Control RF tuning

RF Tuning Range 88 to 108 MHz

Intermediate Outputs IF (10.7 MHz), baseband

Indicator Deviation (switchable between WBFM and NBFM)

PM/NBFM Section

Input Frequency 10.7 MHz

Input Impedance 2 inputs at 50 Ω

Input Level Sensitivity 3 mV (typical for 100 mV p-p at NBFM audio output)

Audio Outputs



Parameter Value

L, R, L + R Bandwidth 50 Hz to 15 kHz

SCA, NBFM, PM Bandwidth 200 Hz to 3 kHz

Impedance 1 kΩ (all outputs)


Test Points 35

Indicators Center tuning, signal level, pilot (19 kHz), deviation display (2½ digits), Power ON




Baseband Channel / Brickwall Filter (Optional) 581632 (9435-00)

The Baseband Channel / Brickwall Filter is designed for use with the Time-Division Multiplexer, Model 9460, the Time-Division Demultiplexer, Model 9461, and the T1/CEPT PCM Transceiver, Model 9462. Other modules that can be used with the Baseband Channel / Brickwall Filter are the Line Coder, Model 9464,

and the Line Decoder, Model 9465.

The Baseband Channel section of the module provides the frequency characteristics of a twisted pair of wires. The line length simulated is selectable between 0.15, 0.30, 1, and 2 kilometers. An auxiliary noise input is provided for noise injection. Input and output impedances are 120 S and coupling is either DC or AC (10 kHz). When AC coupling is selected, both the input and output connectors have a balanced (ungrounded) characteristic.

The Brickwall Filter creates heavy intersymbol interference (ISI) conditions. The filter has a very sharp low-pass characteristic that cuts off at 60 dB per decade. Again, input and output impedances are 120 Ω and can be either DC or AC (balanced) coupled.



Baseband Channel

Maximal Input Voltage 3 V p-p

Input Impedance 120 Ω

Noise Input

Maximal Output Voltage 3 V p-p with 120 Ω load

Frequency Range

DC Coupling 0-15 MHz with 0.15 km line length

0-9 MHz with 0.30 km line length

0-1 MHz with 1.0 km line length

0-100 kHz with 2.0 km line length

AC Coupling 10 kHz to 15 MHz with 0.15 km line length

10 kHz to 9 MHz with 0.30 km line length

10 kHz to 1 MHz with 1.0 km line length

10 kHz to 100 kHz with 2.0 km line length


Impedance 500 Ω

Frequency Range 0-15 MHz

Brickwall Filter

Maximal Input Voltage 3 V p-p



Parameter Value

Input Impedance 120 Ω

Slope 60 dB/decade

Maximal Output Voltage 3 V p-p with 120 Ω load





Time Division Multiplexer (Optional) 581674 (9460-00)

The Time-Division Multiplexer provides training in the principles of time-division multiplexing (TDM). This technique, commonly used in telephone systems because of the ease with which multiplexed signals can be switched, sequentially combines separate signals for transmission in a common channel. Although TDM techniques are generally used for digital signals, it is

also interesting and informative to transmit sampled analog signals.

The Time-Division Multiplexer has inputs for 4 signals. The signals can be either analog or digital. An internal digital data generator can be used to produce 8 bits of data on each of the 4 channels. The bit sequences are set by 4 banks of 8 DIP switches located on the module printed circuit board (pcb). The internal generator bit rate can be adjusted over a frequency range of 0 to 200 kHz.

The TDM rate can also be any frequency up to 200 kHz. It is selected by an external clock. Both the bit rate and TDM rate clocks are independent.

A set of eight test points is provided for more in-depth study. Eight fault-insertion switches are also located on the pcb.

All inputs and outputs are fully protected against erroneous connections.



Channel Inputs

Voltage ±5 V or TTL

Impedance 10 kΩ

Clock Inputs

Voltage TTL


Clock Output

Voltage TTL


Channel Source Internal or external


Test Points 8






Time Division Demultiplexer (Optional) 581677 (9461-00)

The Time-Division Demultiplexer provides training in the technique of recovering time-division multiplexed signals. This technique separates a TDM signal into a certain number of signals available at different output channels. The Time-Division Demultiplexer can be interconnected with the Model 9460 Time-Division Multiplexer. The module has inputs for

the TDM signal as well as for the TDM clock. Internal sample-and-hold circuits allow demultiplexing with minimum filtering at each of the 4 outputs.



TDM Input

Voltage ±5 V

Impedance 10 kΩ

Clock Input

Voltage TTL


Channel Outputs

Voltage ±5 V

Impedance 600 Ω



Test Points 16




T1/CEPT PCM Transceiver (Optional) 581680 (9462-00)

The T1/CEPT PCM Transceiver provides training in PCM-TDM techniques.

The most common forms of time-division multiplexing used by telephone systems are T1 (also known as DS1) in North America and Japan, and CEPT (also known as PCM-30) in

Europe.

In the North American system, 24 channels of 64 kbits/s sampled audio signals are multiplexed. The bit stream produced is at a rate of 1.544 Mbits/s, which includes one bit that is added to each frame (group of 24 channels) for synchronization purposes.

In the European system, 30 channels of 64 kbits/s sampled audio signals are multiplexed. Including 2 eight bit framing and control channels, the bit stream thus produced is at a rate of 2.048 Mbits/s.



The T1/CEPT PCM Transceiver can be set to operate in either T1 (DS1) or CEPT mode.

The transmitter section provides an input connector for use with the Model 9444 PCM Encoder. This single-channel input signal can be inserted in any one of the 24 (T1) or 30 (CEPT) channels. The other channel signals are generated internally by a built-in data generator.

Outputs are provided for frame, channel, and bit clocks. All framing, signaling, and alarm functions are handled internally by the module. Internal DIP switches are used to configure these options. The T1/CEPT output signal is normally connected to the T1/CEPT input on the receiver section, as is the clock signal.

The T1/CEPT signal can also be looped to the Model 9463 Clock Recovery module so as to produce an independent clock signal for use in the receiver. This technique is more realistic and provides training in clock recovery techniques.


Power Requirement Connection to the Power Supply / Dual Audio Amplifier, Model 9401

External Input

Voltage TTL

Clock Input

Voltage TTL

Frequency (T1/CEPT) 1.544/2.048 MHz

T1/CEPT Input

Maximal Voltage 5 V rms

Impedance 120 Ω balanced

Mux Output

Voltage TTL

Clock Outputs

Voltage TTl

Frame Frequency 8 kHz

Channel Frequency (T1/CEPT) 192/256 kHz

Bit Rate (T1/CEPT) 1.544/2.048 MHz

Transmitter/Receiver Monitor Outputs

Voltage TTL

Reset Output

Voltage TTL

T1/CEPT Output

Voltage 8 V p-p

Impedance 120 Ω balanced

Receiver Output

Voltage TTL

One-Channel Data Output

Voltage TTL

Trigger Output

Voltage TTL

Frequency 8 kHz

Modes of Operation

Modes of Operation T1 with bit 7 stuffing

T1 with B8ZS coding

CEPT with HDB3 coding

Multiplexer Operation

Description Multiplexes 23/29 (T1/CEPT) channels with 1 selectable external or internal channel

External Mode All channels fed by external data input signals

Internal Mode (selectable with the internal switch) Data pattern of the internal data generator is selectable with internal switches

Demultiplexer Operation Circuit samples one channel signal of 24/30 (T1/CEPT) channels and feeds it to the one channel data output


External Test Points 8

Internal Test Points 16





Parameter Value

5 kg (11 lb) 5 kg (11 lb)

Clock Recovery (Optional) 581683 (9463-00)

The Clock Recovery provides training in the technique of recovering clock (or bit timing) signals from baseband data signals. The Clock Recovery module provides a recovered clock signal for the Model 9462 T1/CEPT PCM Transceiver.

The module has two modes of operation. The analog mode permits

recovery of a clock signal at a fixed frequency of 1.544 MHz. It uses a band-pass filter with a very sharp frequency response.

The digital mode of operation is based on a digital PLL. A local clock oscillator drives a digital divider that resets to zero whenever a transition occurs in the input data. The frequency of operation of this circuit is variable between 0.2 and 20 MHz. The digital divider division ratio can be adjusted to 8, 16, 32 or 64 counts. This feature allows the reduction of jitter to be observed as the number of counts is increased.

The module has an input for the data signal and outputs for the local and recovered clocks. Seven test points and eight fault insertion switches are also provided on the module. All inputs and outputs are fully protected against erroneous connections.



Data Input

Voltage TTL

Maximal Data Rate 2.5 MBd in digital mode

Local Clock Output

Voltage TTL

Frequency Range 200 kHz to 20 MHz

Impedance 50 Ω

Mode of Operation

Mode of Operation Analog

Digital with selectable dividers: 8, 16, 32, 64

Recovered Clock Output

Voltage TTL

Impedance 50 Ω

Operating Frequency

Analog Mode 1.544 MHz

Digital Mode 3 kHz to 2.5 MHz


Test Points 7






Line Coder (Optional) 581686 (9464-00)

The Line Coder provides training in the principles of line coding. Line codes maintain timing information in baseband signals.

Line coding techniques facilitate timing recovery in data transmission systems. Different line codes facilitate the synchronization of signals but may require larger bandwidths. The Line

Coder provides the following line codes:

• Polar (positive and negative)• RZ (Return to zero)• Biphase (Manchester)• CMI (Coded Mark Inversion)• AMI (Alternate Mark Inversion)• B3ZS (Bit 3 Zero Suppression)• HDB3 (High Density Bipolar 3)• Duobinary (Partial Response Signaling)

The Line Coder is also provided with a data scrambler. This scrambler is normally used to introduce a minimum number of transitions in given data streams. The scrambler can be turned on or off. The module has inputs for data and clock signals and an output for the coded data. All inputs and outputs are fully protected against erroneous connections.

The line coding modules (Models 9464 and 9465) are intended for use with the Baseband Channel / Brickwall Filter, Model 9435.



NRZ Data Input

Voltage TTL

Maximal Data Rate 2 MBd

Clock Input

Voltage TTL


Scrambler Output

Voltage TTL

Impedance 50 Ω

Codes Provided Polar, RZ, Biphase, CMI, AMI, B3ZS, HDB3, Duobinary

Coded Data Output

Nominal Voltage 3 V p-p with 120 Ω load

Impedance 120 Ω


Test Points 7






Line Decoder (Optional) 581689 (9465-00)

The Line Decoder is provides training in the techniques of line decoding. This module is normally used with the Line Coder, Model 9464.

The line codes accepted are the same as those generated by the Line Coder. A data descrambler can also be placed in-circuit. The module has inputs for coded data and for a clock signal.

Decoded and descrambled (if selected) outputs are also available on the module.



Coded Data Input


Maximal Data Rate 2 MBd

Impedance 120 Ω

Clock Input

Voltage TTL


Input Codes Polar, RZ, Biphase, CMI, AMI, B3ZS, HDB3, Duobinary

Decoded Data Output

Voltage TTL

Impedance 50 Ω

NRZ Data Output

Voltage TTL

Impedance 50 Ω


Test Points 7




Dust Cover (Modules) (Optional) 587452 (9494-00)The Dust Cover is a flexible fabric cover specially designed to protect the modules of the Digital Communications Training Systems, Series 8085, against the accumulation of dust during extended storage periods.

Dust Cover (Module Rack) (Optional) 587453 (9494-10)The Dust Cover is a flexible fabric cover specially designed to protect a module rack of the Digital Communications Training Systems, Series 8085, against the accumulation of dust during extended storage periods.



Reflecting the commitment of Festo Didactic to high quality standards in product, design, development, production, installation, and service, our manufacturing and distribution facility has received the ISO 9001 certification.

Festo Didactic reserves the right to make product improvements at any time and without notice and is not responsible for typographical errors. Festo Didactic recognizes all product names used herein as trademarks or registered trademarks of their respective holders. © Festo Didactic Inc. 2020. All rights reserved.

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P. +49(0)711/3467-0F. +49(0)711/347-54-88500

Festo Didactic Inc.

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