Hot to Commission and Troubleshoot Profibus & Ethernet Networks

Jim Ralston - Softing| Oct 24, 2019

Topics

• Softing Introduction

• Industrial Network Trends & Risks to Production

• PROFIBUS Commissioning & Troubleshooting– Best practices for Profibus

• Ethernet/PROFINET Certification, Qualification & Troubleshooting

– Best practices for Ethernet

• Questions?

▪ Global Headquarters in Munich, Germany

▪ Founded 1979, Publicly traded since 2000

▪ Profibus International Board Member

▪ OPC Foundation Founding Member

▪ North America headquarters in Knoxville, TN

Softing Inc.

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Profibus Tester - 5

dataFEED OPC

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edgeGate

uaGATE SI

Industrial Networks – Media is the Foundation

Cabling is Layer 1 (foundation)

Proper Cabling Practices Increase Downtime

• According to an ISA.org online article, industrial network

failures accounted for 35% of total failures in plant

automation.

• Physical deterioration, electrical failure, or poor installation

and maintenance practices can all lead to unreliable network

performance.

− loss of critical data

− system downtime

− even catastrophic failure

Yesterday

Today Emerging Tomorrow

Network

Serial PROFIBUS Profinet(10/100B

T)

Profinet(1000BT)

Profinet/TSN

(2.5GB-T)

Profinet/TSN

(5GB-T)

Profinet/TSN(10GB-T)

Data Rate(kbit)

1.2 4.8 9.6 31.25

12,000 10,000 to 100,000

1,000,000 2,500 5,000 10,000,000

0.0012 0.0048 .0096 .03 12 55

1000

2500

5000

10,000

Data Rate (mbps)

The Industrial Network Speed Revolution

Profibus Troubleshooting

PROFIBUS is a Bus Topology (daisy-chain cabling)

Profibus Testing Introduction

Most problems in PROFIBUS networks are caused by

▪ Improper segment termination (missing, unpowered or excessive)

▪ Segments that are too long or lines that are too short

▪ Excessive number of devices in a segment

▪ Spur (drop, branch) lines

▪ Sharp cable bends

▪ Wrong type of cable

▪ Improper wiring, grounding and/or shielding

▪ Damaged cable (breaks, shorts, corrosion)

▪ Cable routing in environments subject to strong electromagnetic interference

▪ Wrong configuration of PROFIBUS parameters, GSD files, etc .

PROFIBUS Tester 5

PROFIBUS Tester 5 is a powerful tool capable of

performing comprehensive testing of PROFIBUS DP

segments.

One tool, many functions:

▪ Signal tester

▪ Cable tester

▪ Storage oscilloscope

▪ Protocol analyzer

▪ Frame recorder

▪ Trend recorder

▪ Master simulator

▪ PROFIBUS PA testing (w/optional adapter)

Portable Battery-Powered with 3.5” Graphical Display

Operation Modes

Two modes of operation:

▪ Stand-alone mode

▪ PC mode

Measurement Locations

Measurement Locations

Handheld: Test Function – Cable Test

• Master disconnected – use when production is down or installation

• Complete distance to fault results (opens, shorts, termination problems)

• Quick way to determine cable faults

• Similar to BT-200 function

Handheld: Test Function – Bus Status

• Measurement on active system

• Quick determination of Diagnostic Messages (Node & Slot)

Handheld: Test Function – Signal Quality

• Measurement on active system

• Reports Signal Quality level at each Node (note we recommend two

measurements)

Handheld: Test Function – Oscilloscope

• Measurement on active system

• Displays waveform at connection point (voltage levels, noise/ringing)

Troubleshooting with the PROFIBUS Tester 5

Quick determination of Bus Communications and Bus Physics Health

First indication:

There is a problem !

Communication is okay

=> Traffic Light is green

Signal quality is critical:

Some nodes show bad signal quality

=> Traffic Light is yellow

=> Further Analysis required

Troubleshooting with the PROFIBUS Tester 5

• Quick determination of Signal Quality at each node

• Signal Quality may be trended over time

Troubleshooting with the PROFIBUS Tester 5

• Oscilloscope waveform & Signal/Noise measurement

• Click on each node to view (no need to move Tester)

Master

2 7 9 23 34 51 71

RR

R

R R

R

5V5V

Typical Issues in a PROFIBUS Network: Sample Network

Take measurements from both ends:

- Master 2

- Slave 71

Measurements from right side

(slave 71)

Measurements from left side

(master 2)

Typical Issues in a PROFIBUS Network

Case 1: High Line Resistance

Results:

Test results on the left end:

- Good quality values for stations 2 – 34

- Bad quality values for stations 51 & 71

Test results on the right end:

- Bad quality values for stations 2 – 34

- Good quality values for stations 51 & 71

➔ Reversal of Q-Levels!

Interpretation:

The test result from the right side is almost a mirror image of the one from the left side. This is a clear indication of a high resistance in the network (corrosion, bent cables, long cables, etc.)

In this case the problem is located between slaves 34 and 51.

Master

2 7 9 23 34 51 71

RR

R

R R

R

5V5V

Typical Issues in a PROFIBUS Network

Case 1: High Line Resistance

Typical Issues in a PROFIBUS Network

Case 2: Missing Terminator

Quality is bad seen from one end only:

Master

2 7 9 23 34 51 71

RR

R

R R

R

5V5V

Take additional measurements at other locations to get a better picture of what is happening…

Master 2 Slave 7 Slave 23 Slave 71

Results:

The quality from one end declines gradually as you move to the other end:

Typical Issues in a PROFIBUS Network

Case 2: Missing Terminator

2 7 9 23 34 51 71RR

R

R R

R

5V 5VMaster

You can see the reflections in the

oscilloscope view for “Master 2”,

seen from the “Slave 71” test point.

Interpretation:

The problem is caused by signal reflections in the segment, due to a missing terminator at slave 71.

This type of problem is normally generated at the test location that shows most stations with bad signal quality levels.

Typical Issues in a PROFIBUS Network

Case 2: Missing Terminator

Termination Details

Typical Issues in a PROFIBUS Network

Case 3: Wire Break

Results:

Test result from the left end: stations 53 and 71 are timing out

Test result from the right end: all stations are timing out

Typical Issues in a PROFIBUS Network

Case 3: Wire Break

Master

2 7 9 23 34 51 71

RR

R

R R

R

5V5V

Interpretation:

Devices 51 and 71 can’t be seen from the left end, and nothing can be seen from the right end. These results indicate that the problem must be a break of one or both lines between stations 34 and 51.

Troubleshooting with the PROFIBUS Tester 5• Troubleshoot Bus Communication problems

Troubleshooting with the PROFIBUS Tester 5• Quick view of Station Statistics – identify problem nodes

Below are examples of diagnostic messages in plain text from a WAGO slave and from a Siemens Diagnose Repeater.

Reading the log gives a simple indication of the problem.

Diagnosis View

Troubleshooting with the PROFIBUS Tester 5

• Display Diagnostic Messages as Text not Hex

PROFIBUS Diagnostics Suite: Frame Recording• Complete frame & data recording – with trigger options

PROFIBUS Diagnostics Suite: Commissioning Report

Industrial Networks – The Need for Speed!

• First Generation Plant Networks

- HMI/SCADA & PLC Programming

- Controller Messaging (unscheduled)

Simple, relatively slow speed (10Base-T)

• Modern Plant Networks – an evolution

- Real Time I/O

- Drives/Motion

- Vision Systems/Video Monitoring

- More devices to monitor/collect data

More complex, faster speeds needed! (1000Base-T+)

Best Practices for Industrial Ethernet Testing

Ethernet is a Star Topology using Switches (or hubs)

Point-to-point cabling

Why is Complete Cable Testing Important?……..

• As network bandwidth (data rate) increases…..

− Carrier frequency increases

− Impedance (attenuation) increases

− Signal/noise ratios tighten

− Crosstalk between pairs increase

• High frequency signals traveling over copper

− Poor wiring = poor network performance (DOWN TIME)

− DC Continuity (zero baud) is not a complete test!

It’s all about the pairing!

Ethernet Standards and Cable Frequency

StandardSpeed(Mbit/s)

Category Standard

PairsMax

Length

CableFrequency

(MHz)

10BASE-T 10 Cat 3 2 100m 16

100BASE-TX 100 Cat 5 2 100m 100

1000BASE-T 1,000 Cat 5e 4 100m 100

2.5GBASE-T 2,500 Cat 5e 4 100m 100

5GBASE-T 5,000 Cat 6 4 100m 250

10GBASE-T 10,000 Cat 6A 4 100m 500

40GBase-T 40,000 Cat 8 4 40m 2,000

• Faster networks run at higher

frequencies

− New 2.5/5 Gbit/s bridge the gap

− Will existing cable support it?

− Is new cabling required?

Best Practices for Industrial Ethernet Testing

Most problems in Profinet (Ethernet) networks are caused by:

▪ Poor cable/connector quality

▪ Poorly terminated Ethernet plugs/outlets (lack of installation training)

▪ Worn Ethernet RJ45 plugs – frequent insertions & machine vibration

–Plugs instead of outlets/jacks being used on long runs

▪ Poorly installed cable runs – cable routing, bend radius, tie wraps....

▪ Cable routing in environments subject to strong interference

▪ Lack of, or improper sheidling

▪ Network speed exceeds cable rated category

▪ Network/Device configuration issues

• Verifying

− Basic test of conductivity (DC)

− Wire map check

• Qualifying

− Determining Ethernet Performance (bit error rate)

− Troubleshooting (distance to wiring fault)

• Certifying

− Standard acceptance test for networks (cert report)

− Testing wire map, length & crosstalk noise levels

− Location to fault/troubleshooting (wiring & pairing issues)

• Active Monitoring/Alarming

− Real-time network monitoring

− Preventative alarming

− Inventory/health

− Packet level analysis

Ethernet Test Levels & Types

Cable testers have a range of capabilities: Our focus will

be on Certification and Qualification

What Certification is All About

• Ensuring that the cable infrastructure MEETS the TIA 568 CAT standards- The network DEPENDS on Layer One!

• Reducing start-up time

• Reducing “finger pointing” when network problems arise- 80+% of industrial network problems are cabling oriented!

• A REQUIREMENT for the manufacturers warranty (Belden, Panduit, etc.)

• Certification is PART of the TIA 568 standard

• Certification is the NORM for commercial installations – why not industrial?

• Certifiers also make excellent troubleshooting tools – reduce downtime

Cable vendors will warranty their wiring and connections for periods up

to 25 years if installations are Certified with approved equipment

Example Cable Certification Report

NetXpert XG – Qualification & Network Test Tool

IT Networks. All rights reserved.

47

• Qualifies data cables up to 10GBit/s

– Base model qualifies 1 Gbit/s

– Upgradeable to 2.5G/5G/10Gbps (future proof)

• Combines 3 different tests for reliable speed results

– Signal/Noise Ratio, BERT, Skew

• Troubleshoots passive and active networks

• SFP/SFP+ for fiber network/BERT testing support

• PoE/PoE+/PoE++ load tests

• Captures Test Results (reports)

• Graphical wire map display

• Measures and displays length for eachpair in feet or meters

• Improperly terminated cables are clearly displayed

• Detects Length to Opens

• Displays crossings, swaps, shorts and split pairs

• Information to guide quick cable repair

NetXpert XG – Cable testing

Copyright © 2019 Softing IT Networks. All rights reserved. 11

Network Tests and Diagnosis• Link Status

• DHCP test

• Network Discovery

• Ping list

• Traceroute• VLAN detection

• PoE/PoE+/PoE++ load test

• IPV4/IPV6 Support

• Discovers CDP and LLDP Protocols

• VLAN detection

• Link Light

NetXpert XG– Active Testing and Troubleshooting

Copyright © 2019 Softing IT Networks. All rights reserved. 14

NetXpert XG– Network Discovery

IT Networks. All rights reserved.

50

Graphical network discovery gives an overview on reachable devices within same subnet Network discovery list-view shows all devices

and lets you directly transfer them into the ping list – Highlights Duplicate IPs

NetXpert XG– Tools

IT Networks. All rights reserved.

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Show PoE class and perform a load test

Perform a single BERT test, define how long the test runs and get detailed results

Continuous wire map testing

NetXpert XG - Summary

IT Networks. All rights reserved.

52

• Answers crucial questions

– Will the cable support my application (data rate?)

– Does my cable have a problem? Is it repairable?

– What do I need to repair it?

• Network Troubleshooting Tool

– Active network testing

– PoE measurement

• Reports – test results/network documentation

Fiber Optic Cable Testing

• WireXpert 4500 with MM SM Fiber

• Tier 1 Fiber Optic cable certification

• Optical length & loss

• Fiber Microscope

• Inspection tool for connector end faces

• FiberXpert OTDR

• Detailed attenuation with distance to losses

• Excellent fiber troubleshooting tool

Fiber Optic Cable Testing

• WireXpert 4500 with MM SM Fiber

• Tier 1 Fiber Optic cable certification

• Optical length & loss

• Fiber Microscope

• Inspection tool for connector end faces

• FiberXpert OTDR

• Detailed attenuation with distance to losses

• Excellent fiber troubleshooting tool

• XpertClean Kits

• Cleaning kits for fiber connectors

• 90% of fiber network issues are due to dirty connections

Questions?

www.Softing.us/sia

Jim Ralston724-554-8498jim.ralston@softing.us