E1529 Strain Multi-Channel Strain Measurement Product T Conway Taking the stress out of strain...
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Transcript of E1529 Strain Multi-Channel Strain Measurement Product T Conway Taking the stress out of strain...
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Taking the stress out of strain measurements.
B RIDGEP OW E R
S HUNTCA L. R
12 VOLTS YSTE MP OW E R+ - GND
DA TA I/FTO
E 1415A
b u s
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b u s
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b u sb u s
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72.93
182.2
B RIDGEP OW E R
S HUNTCAL. R
12 V OLTS YS TE MP OW E R+ - GND
DATA I/FTO
E 1415A
B RIDGEP OW E R
S HUNTCAL. R
12 V OLTS YS TE MP OW E R+ - GND
DATA I/FTO
E 1415A
B RIDGEP OW E R
S HUNTCAL. R
12 V OLTS YS TE MP OW E R+ - GND
DATA I/FTO
E 1415A
Agilent E1529A: Remote Strain Bridge Conditioning
E1529 Strain Multi-Channel Strain Measurement Product T Conway
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E1529 Strain Multi-Channel Strain Measurement Product T Conway
E Trainer for E1529ATom Conway
Phone
Personal line: 970-679-3863
Loveland VXI support line: 970-679-2545
Loveland, Colorado USA
Office hours 8am-5pm Mountain time zone
Email: [email protected] or
Use the E trainer to:
Answer questions on the E1529A material
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Customer Requirements
User Needs The Customer's Words
Flexible configuration "Strain gages and bridgeconfigurations change often."
Easier wiring "Connecting individual wires istime consuming."
Reduced wiring "Remote mux'ed conditioningwould greatly reduce the wiringcosts."
Combined conditioning forstatic and dynamic
"Buying separate conditioningis too expensive."
Lower cost for qualityconditioning
"Our budget always limits thenumber of channels we canbuy."
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Remote Strain Conditioning
• 32 Channel Remote Unit reduces wiring• Low Cost wiring using Telecom connectors• Outputs for static or dynamic measurements• Measure 6000+ gages in 1 VXI mainframe• Ideal for strain gage tests
– structure test– fatigue / durability test– large channel counts
Agilent E1529A
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Applications and Customers• Airframe Structural and Fatigue Test
– Lockheed/ Northrop - Hawthorne CA– Boeing - Long Beach CA– Lockheed - Palmdale CA
• Rocket and Satellite Structural Test– Boeing - Huntington Beach CA
• Wind Tunnel Flight Load Test– Boeing Helicopter - Delaware– NASA AEDC - Tullahoma TN
• Structural Test System Integrators– MTS Systems Inc - Minn. MN– Sverdrup Technology - Tullahoma TN
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Strain Gage Primer ()
Principal Axis
Gage Length
• Strain ()= Length / Unit length– Typ 5-15000
• Gage proportional to 1/A– Typ Values 120, 350, 1000
• Gage Factor = ( / )/(L/L)– Typ Values 1.5 - 2
• Transverse Sensitivity = GFt/GFl– Typ 0 to 10%
• Temp. Expansion Coefficients– Same as base material
Sample Calculation: 350 Gage, 10 , GF = 2
=?
2 =(/350)/(10 x 10^-6) = (10x10^-6)(2)(350) = 0.007
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Measuring Strain Gages
Values are small– micro or milli ’s
measurements require Wheatstone bridge
• Vout = R3 - R2 Vin R3+Rg R1+R2– Typ Vin = 0.5 to 5.0
Volt = (Rg /Rg)/GF
Sample Calculation: 350 Gage, GF = 2, Vin=2, Vout=-72V
R1=R2=10k, R3= 350, =?Rg=R3/[(Vout/Vin)+R2/(R1+R2)]-R3Rg=350/[(-72x10^-6)/2)+(10/20)]-350
Rg= 349.950=(.05/350)/2=-71.43
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Programming and Acquiring Data
Programs are downloaded from host computer just prior to run time.Last command is INIT which starts the card
Runs independent of host after that - exceptWhen FIFO half full it sends flag to host to do a block transfer of 32K readings from dual ported FIFO
Also, in host a timing loop is setup to peridoically read the data in the CVT (for display or action)
DSP
A/D64 ChlMux
EUconv
64KFIFOMem
CVT
Calibrator
SCPs
VX
I Bu
s
Term
inal
Blo
ck A
ssy
HP VEE
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Agilent’s Previous Approach to Strain Internal Signal Conditioning
• Strain requires two SCP’s – Bridge SCP E1506/07A– Analog Measurement SCP E1508/09A
• Fixed Internal Excitation• 4-wire measurement• 2 SCP’s per 8 gages
– 32 Ch per 64 Ch VXI card• Issues
– Cost– Cal method, Shunt Value– Excitation
– Value/Measurability
Terminal BlockAssy
M easurement SCPmodule
Completion/Excitationmodule
2K
2K
120or
350
StrainGage
29.4KShunt
To HP E1413CE1415AE1422AE1419AE1313A
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Original Agilent Strain Configured System Vs New E1529A System
SUT
1000'
SUT
1000'
E1529 Strain Multi-Channel Strain Measurement Product T Conway
E1529A Product Description
• 32 channel mux'd remote signal conditioning unit allows up to 1000' separation from DAC system with one telecom cable
• Field wiring uses RJ-45 shielded telecom connectors for density, ease of use, reliability, and low-cost
• Amplification and Filter per channel• Buffered (>100 kHz BW) output per channel
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Choosing the RJ-45 Connector
• Reliability• Solid Design• Easy to Assemble• Did well in our QA tests
E1529 Strain Multi-Channel Strain Measurement Product T Conway
E1529A Product Description• Programmable support for full, half, and quarter
bridge bending strain measurements.• Programmable support for 120, 350, and user-
chosen bridge completion resistors• User provided bridge excitation in 8-channel banks• Amplifier and Filter per channel for static strain
measurements• Buffered outputs (pre-filter) for dynamic strain
measurements• Programmable via RS-485 port for dynamic-only
applications
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Product Features
• One E1422A (modified E1415A) supports up to 512 channels of strain measurement
• Arbitrary scan lists for static measurements• mx+b correction on all channels• Self-calibration < 5 minutes for 1000
channels• Greater than 20 kSa/sec throughput rate w/
E1422A• Temperature stable E1529A operation
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Built-in Strain EU Conversion
• Conversion to strain units done automatically by DSP using unstraind bridge reading and GF
• Can always measure bridge output voltage for use with biaxial, Poisson, and Rosette strain gage configurations.
• Quarter bridge strain conversion is a quadratic approximation. See error analysis in manual.
• Good Reference - Application Note 290-1, “Practical Strain Gage Measurements” (Pub 5952-8880)
E1529 Strain Multi-Channel Strain Measurement Product T Conway
E1422A Terminal Block Ass’yFront, Rear and Assembled Views
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Static Strain Configuration
Max channel countfor each E1422A A/D
16 x 32 ch = 512 ch
DSP
A/D64 Chl
MuxEU
conv
64KFIFO
Mem
CVT
CalibratorSCPs
32 channels1
2
3
16
32 channels
32 channels
32 channels
Max channels/mainframe = 6,144
E1529A E1422A
8 ea.E1539A
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Detail of Static Configuration
Max channel count for each A/D
16 SCPs * 32 Ch/SCP = 512 Channels
12 A/Ds * 512 Ch= 6,144 Channels
E1529A
E1529A8/
8/
Analog Msmt +
Analog Msmt -
Cal +
Cal -
RS-485 +
RS-485 -
Trig +
Trig -
32 RJ-45 inputs
2 - 37p D Dynamic Inputs
1 RJ-45 8p Data I/F
1 - 9p D Bridge Exitations
2 - screw term RshuntE1422A
E1539A
Sta
ndar
d E
1422
A T
/B
Computer
Computer-VXI Interface
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Greater than 20 kSa/sec total
• The E1422A minimum sample interval is 40 us.
• Min Scan time = (No channels + 3) X 40 us + 80 us
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Dynamic Strain Configuration
DSP
A/ D64 ChlMux
EUconv
64KFIFOMem
CVT
CalibratorSCPs
32 channels1
2
3
5
32 channels
32 channels
32 channels
DSP
A/D64 ChlMux
EUconv
64KFIFOMem
CVT
CalibratorSCPs
DSP
A/D64 ChlMux
EUconv
64KFIFOMem
CVT
CalibratorSCPs
DSP
A/D64 ChlMux
EUconv
64KFIFOMem
CVT
CalibratorSCPs
E1432A
1
2
3
10
Max ch/mainframe = 160
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Detail of Dynamic Configuration
Max Ch = 160 per M/F
E1422AE1529A
E1529A
8/
Analog Msmt +
Analog Msmt -
Cal +
Cal -
RS-485 +
RS-485 -
Trig +
Trig -
32 RJ-45 inputs
2 - 37p D Dynamic Inputs
1 RJ-45 8p Data I/F
1 - 9p D Bridge Exitations
2 - screw term Rshunt
E1432A
E1432A
16/
16/
E1539A
Sta
ndar
d E
1422
A T
/B
Computer
Computer-VXI Interface
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Product Structure
• E1529A Remote Unit• E1422A VXI DAC Module• E1539A SCP
• Typical 1200 channel static system • < $240/ch including mainframe/E1422A
• Typical 320 channel dynamic system • < $1050/ch including
mainframe/E1432A/E1562D
E1529 Strain Multi-Channel Strain Measurement Product T Conway
WagnerVoltage enable
+P
+Ps
+S
-S
-Ps
-P
-Rcal
+Rcal
StrainBridge
8-pin telcomconnector (RJ-45)
Cal-Cal+
350
120
customer
10K
10K
10K
off for full bridge
10K
+
-
OptionalFilter
2,10,100Hz
+Ps-Ps
2:1Mux X2
Instrument.Amplifier
Buffer
Dynamic StrainOutput
To HP E1422A(E1539A SCP)
+ Excitation
- Excitation
X1Buffer
InternalRcal
50KLocal Rcal
Enable
Remote RcalEnable
Int/Ext RcalSelect
Excitation Sensefrom CHs 1-31
32:1Mux
CH31
CH00
CH01
32:1Mux
CH31
CH01CH00
Bridge Sensefrom CHs 1-31
External customershunt cal resistor
terminals
-Rcal
+Rcal
RJ-45
enable excitationCHs 0-7
Quarter Bridge Measurement
CurrentLimit
Excitationto CHs 1-7
E1529 Strain Multi-Channel Strain Measurement Product T Conway
WagnerVoltage enable
+P
+Ps
+S
-S
-Ps
-P
-Rcal
+Rcal
StrainBridge
8-pin telcomconnector (RJ-45)
Cal-Cal+
350
120
customer
10K
10K
10K
off for full bridge
10K
+
-
OptionalFilter
2,10,100Hz
+Ps-Ps
2:1Mux X2
Instrument.Amplifier
Buffer
Dynamic StrainOutput
To HP E1422A(E1539A SCP)
+ Excitation
- Excitation
X1Buffer
InternalRcal
50KLocal Rcal
Enable
Remote RcalEnable
Int/Ext RcalSelect
Excitation Sensefrom CHs 1-31
32:1Mux
CH31
CH00
CH01
32:1Mux
CH31
CH01CH00
Bridge Sensefrom CHs 1-31
External customershunt cal resistor
terminals
-Rcal
+Rcal
RJ-45
CurrentLimit
Excitationto CHs 1-7
enable excitationCHs 0-7
Full Bridge Measurement
E1529 Strain Multi-Channel Strain Measurement Product T Conway
WagnerVoltage enable
+P
+Ps
+S
-S
-Ps
-P
-Rcal
+Rcal
StrainBridge
8-pin telcomconnector (RJ-45)
Cal-Cal+
350
120
customer
10K
10K
10K
off for full bridge
10K
+
-
OptionalFilter
2,10,100Hz
+Ps-Ps
2:1Mux X2
Instrument.Amplifier
Buffer
Dynamic StrainOutput
To HP E1422A(E1539A SCP)
+ Excitation
- Excitation
X1Buffer
InternalRcal
50KLocal Rcal
Enable
Remote RcalEnable
Int/Ext RcalSelect
Excitation Sensefrom CHs 1-31
32:1Mux
CH31
CH00
CH01
32:1Mux
CH31
CH01CH00
Bridge Sensefrom CHs 1-31
External customershunt cal resistor
terminals
-Rcal
+Rcal
RJ-45
enable excitationCHs 0-7
Half Bridge Measurement
CurrentLimit
Excitationto CHs 1-7
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Benefits of Agilent E1529A Remote Strain Conditioning System
• Reduced Cost• Reduction of Complexity and Cost of Wiring • Excitation Features• Calibration• Dynamic Strain Conditioning
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Reduced Costs:Typical 512 Channel Configuration
512 Chl - Qty List Price Total
E1422A 1 $6600 $6600
E1539A 8 $900 $7200
E1529A 16 $5900 $94,400
HP-6641A Pwr Sply 2 $2420 $4840
Total $113,040
Price/Chl $221
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Reduced Costs: Costs by Number of (32 Ch) E1529A Remote Muxes
• Cost of HP E1529A per channel is significantly less than old version of strain for large channel count systems
• Shown here are est. costs for new HP Strain Implementation– HP E1422A VXI card– HP E1539A SCP– HP E1529A Mux
• Shown original costs– Includes: Strain SCP, AI,
Remote Panel
$0
$100
$200
$300
$400
$500
$600
0 500 1000 1500
# Chls$/C
hl
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Cost Comparison: Old System
Qty Product # Description Cost$ Ext Cost$ Cost$/Chl
1 E1413C ScngA/D 6,600$ 6,600$ 206$ 4 E1506A StrainBridge 800$ 3,200$ 100$ 4 E1509A Analog Input 800$ 3,200$ 100$ 2 E1586A Remote Panel 700$ 1,400$ 44$ 2 E1588A Cable 100$ 200$ 6$
80 hrs Tech Lbr I/F 70$ 5,600$ 175$ 32 Cables Cables 115$ 3,680$ 115$
23,880$ 746$
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Cost Comparison: New E1529A System
Qty Product Desc Cost Ext Cost Cost/Chl
1 E1422A VXI Card $6,600 6,600$ 8 E1539A SCP $900 7,200$
16 E1529A Mux $5,900 94,400$ 2 6641A PS $2,420 4,840$ 221$ 1 DataComm Cbl $47 47$ 5$
16 PS Cable $115 2,592$ 2 Pwr Dist Pnl $2,880 5,760$ 11$
Total 237$
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Comparing System Prices:Old/New - Agilent/Competition
HP E1413A System
Pacific Instruments (estimated)
uMeasurements (estimated)
HP E1422A System
HP H/W 460$ 400$ 315$ 220$ Connectors + Ass'y 110$ 110$ 110$ 10$ I/F Panel 175$ 175$ 17$ -$ E1586A+ cable 50$ -$ -$ -$ Signal Cable Itself 35$ 35$ 35$ 2$ PS Cable 5$
830$ 720$ 477$ 237$
512 Chl Sys 424,960$ 368,640$ 244,224$ 121,446$ 1000 Chl Sys 849,920$ 737,280$ 488,448$ 242,893$
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Comparing System Prices:Old/New - Agilent/Competition
$-
$100,000
$200,000
$300,000
$400,000
$500,000
$600,000
$700,000
$800,000
$900,000
512 Chl Sys 1000 Chl Sys
HP E1413A System
Pacific Instruments (estimated)
uMeasurements (estimated)
HP E1422A System
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Per Channel Cost ComparisonsOld/New - Agilent/Competition
$-
$100
$200
$300
$400
$500
$600
$700
$800
$900
Per Channel Cost Comparisons
HP E1413A System
Pacific Instruments (estimated)
uMeasurements (estimated)
HP E1422A System
E1529 Strain Multi-Channel Strain Measurement Product T Conway
In Addition: Cost of Cables
• This table shows the cost differential for cables with and without multiplexing
E1529 Strain Multi-Channel Strain Measurement Product T Conway
• Old Way– 16 E1413A’s, 128
SCP’s– 2 Mainframes– 2 Firewire I/O’s– 32 E1586 Rack Panels– 512 Lug cables ($100)
• Total = $280,915• $549 / Channel
• E1529A Way– 1 E1422A, 8 SCP’s– 1 4 slot Mainframe– 1 Firewire I/O– 16 E1529A Remote Units– 512+16 RJ-45 Cables
($20)– 2 HP 6641A Supplies
• Total = $129,720• $253 / Channel
Benefits of Agilent E1529A Reduced Cable Cost - 512 Channel System
Customer Saves $151, 195!
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Benefits of Agilent E1529AReduced Complexity 512 Channel System
• Old Way– 512 Cables 8 Leads
(75m)– 4096 crimped lugs– 4096 terminal screws– 512 75m cables
• 512 long cables• 1 min / screw = 68 hours
• HP E1529A Way– 512 RJ-45 cables (25
m)– 554 crimped plugs– 554 “snap-ins”– 16 300m cables
• 16 long cables• 10 sec / snap = 1.5
hoursCustomer Saves 66.5 Hours!
Customer Saves 20.8 km of cable!
E1529 Strain Multi-Channel Strain Measurement Product T Conway
• Old Way– SCP = 120 or 350
Ohms– Excitation Fixed– Assumed Fixed
– IR comp. difficult– CAL difficult– No Dynamic Output
• HP E1529A Way– Select 120, 350 or
Custom– 4 Excitations / 32
Chan.– Excitation Measured
– accurate IR comp.– *CAL, end to end
auto.– Live Dynamic Output
Benefits of Agilent E1529AImproved Performance and Functionality
Customer gets More Functionality!Customer has More Accuracy!Customer has More Uptime!
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Extended Channel List for E1422AScan List: ROUT:SEQ:DEF (@10000:11631)
Algorithm Input Variable: I10915
First digit = channel data modifier (like E1413) 1 - EU reading to FIFO and CVT 2 - EU reading to CVT only 3 - EU reading to FIFO only 0 - throw away (dummy reading)
Second two digits = E1422A channel number for E1539A channel 0 or 1
Last two digits = E1529A channel number
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Command Sequence
INP:FILT:FREQ 10,(@10000:11731) Selects 10 Hz low pass filter (192 ch list)INP:FILT ON,(@10000:11731) Connects selected filter*CAL? Cal’s E1422 and E1539’sCAL:REM? (@10000:11731) Cal’s E1529’s
FUNC:STR:Q350 (@10000:11731) EU - 1/4 bridge, autorange, GF=2 (defaults), and sets E1529 configuration switchesSTR:GFAC 2.2,(@10000:11731) Sets gage factor (GF) in strain EUSTR:EXC ON,(@10000:11731) Connects excitation supplyROUT:SEQ:DEF (@10000:11731) Defines scan list
MEAS:VOLT:EXC (@10000:11731) Measures Vex and sends it to strain EU..
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Excitation Measurement Note
E1422A/E1529A measures it once and expects it to bestable. Competition measures excitation and bridge output on every scan. Since strain is proportional toVbridge/Vexc, and most strain measurement experts are accustomed to measuring both, this change can be a tough sale. A very stable excitation source power supply is required, or the Vexc measurement should be updated frequently.
E1529 Strain Multi-Channel Strain Measurement Product T Conway
Command Sequence (cont)
MEAS:STR:UNST? (@10000:11631) Measure unstrained bridge voltage and send it to EU & FIFODATA:FIFO:RESET Clear FIFO
OUTP:SHUN INT,(@10000:11631) Selects internal 50 Kohm shuntOUTP:SHUN ON,(@10000:11631) Mux’s shunt to each ch as scannedINIT DATA:FIFO? Read shunt cal results to verify connex and EU (3475 ue for 350 ohm GF = 2)OUTP:SHUN OFF,(@10000:11631) Disconnect shunt resistor
TRIG:COUN n (1 <= n <= 65535, or 0 | INF for continuous)INIT Start Strain acquisition
E1529 Strain Multi-Channel Strain Measurement Product T Conway
The *CAL Advantage
• End to end automatic cal is a big advantage over competition.
• *CAL results in superior system accuracy.• This can be a very important selling point
when considering Tech time and system down time for calibration - as important as cost/ch.