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

b u s

b u s

b u s

b u s

b u s

b u s

b u s

b u sb u s

b u s

b u s

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


DATA I/FTO

E 1415A

B RIDGEP OW E R

S HUNTCAL. R


DATA I/FTO

E 1415A

Agilent E1529A: Remote Strain Bridge Conditioning


Viewing the E1529A Training MaterialThis PowerPoint presentation has Extensive Speaker notes

View both the slide and the speaker notes

using PowerPoint

Do not view with a browzer because the

speaker notes won’t be visible

To view slides and notes in PowerPoint

View > notespage

or

View > speaker notes

To print slides and notes

File > Print then set

Print what: Notes Pages


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

[email protected]

Use the E trainer to:

Answer questions on the E1529A material


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."


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


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


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


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


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


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


Original Agilent Strain Configured System Vs New E1529A System

SUT

1000'

SUT

1000'


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


Choosing the RJ-45 Connector

• Reliability• Solid Design• Easy to Assemble• Did well in our QA tests


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


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


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)


E1422A Terminal Block Ass’yFront, Rear and Assembled Views


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


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


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


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


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


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


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



+P

+Ps

+S

-S

-Ps

-P

-Rcal

+Rcal

StrainBridge


Cal-Cal+

350

120

customer

10K

10K

10K

off for full bridge

10K

+

-

OptionalFilter

2,10,100Hz

+Ps-Ps

2:1Mux X2


Buffer



+ Excitation

- Excitation

X1Buffer

InternalRcal

50KLocal Rcal

Enable

Remote RcalEnable

Int/Ext RcalSelect


32:1Mux

CH31

CH00

CH01

32:1Mux

CH31

CH01CH00



terminals

-Rcal

+Rcal

RJ-45

CurrentLimit



Full Bridge Measurement



+P

+Ps

+S

-S

-Ps

-P

-Rcal

+Rcal

StrainBridge


Cal-Cal+

350

120

customer

10K

10K

10K

off for full bridge

10K

+

-

OptionalFilter

2,10,100Hz

+Ps-Ps

2:1Mux X2


Buffer



+ Excitation

- Excitation

X1Buffer

InternalRcal

50KLocal Rcal

Enable

Remote RcalEnable

Int/Ext RcalSelect


32:1Mux

CH31

CH00

CH01

32:1Mux

CH31

CH01CH00



terminals

-Rcal

+Rcal

RJ-45


Half Bridge Measurement

CurrentLimit



Benefits of Agilent E1529A Remote Strain Conditioning System

• Reduced Cost• Reduction of Complexity and Cost of Wiring • Excitation Features• Calibration• Dynamic Strain Conditioning


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


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


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$


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$


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$


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



HP E1422A System


Per Channel Cost ComparisonsOld/New - Agilent/Competition

$-

$100

$200

$300

$400

$500

$600

$700

$800

$900

Per Channel Cost Comparisons

HP E1413A System



HP E1422A System


In Addition: Cost of Cables

• This table shows the cost differential for cables with and without multiplexing


• 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!


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!


• 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!

S400 E1529 March 2001 T Conway

E1422A/E1529A Programming


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


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..


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.


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


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.

e1529 strain multi-channel strain measurement product t conway taking the stress out of strain...

Documents

strain measurements

remote strain conditioning

view speaker

extensive speaker notes

speaker notes wont

notes file print

gage proportional

gage factor