Eight-Channel Strain Completion & Excitation
Contents
1. L 1dO veos LLA 21 110 YZOG LLA 330 15114 LL 190 VLOS LLA orog 000 i H H H H 4 4 4 i 1 4 1 oe 1 gt F 7 t way see ELLE M 00 02 0081 WEI 00791 n ac AXE 61 00 LI Lee LEE S iie 006 00 8 00 2 KY 9 00 o OOP 007 901 X 010115 VT1506A 07A Strain SCP 23 Spedfications 900 oroz 01 x weng 4 uL EM i i 1 1 i a E O 330 79115 WEOSL LA 330 Jayla 1190 YEOSLLA CH UD OL RT ME A OD PIS tls 100 veog p LA LL 190 vEOSLLA uossioq ISPUHA 00 Ot rt 00 02 00 81 0091 0071 c 008 009 Q0 t 00 9 01 x amis Spedfications 24 VT1506A 07A Strain SCP 0 350 de de e b m U2. The top jumper configures as Agilent HP E1413 Option 16 17 VT1506A 07A ff Any of these three jumpers will connect the Excitation Supply Remove all three jumpers to isolate the excitation supply Figure 15 Isolating the Internal Excitation Supply Connecting the External Supply Note Enter Excitation Voltage Value Use Figure 16 to connect to external supply to the Terminal Module Be sure the Excitation Jumper is removed from the Strain Completion and Excitation SCP before connecting the external supply see Isolating the Internal Excitation Supply above Be sure to keep the removed jumper for future use in case the internal Excitation Supply is to be used later Use the SENSe STRain EXCitation command to enter the value of the external excitation voltage The syntax of the command is SENSe STRain EXCitation excite v G ch list where excite v is the value of the external excitation voltage and ch list specifies the channels of the sense SCP e g VT1501A Direct Input that connects to the bridge not the Strain Completion and Excitation SCP The default value of the excitation voltage is 3 9 V which is also the value of the internal excitation supply The minimum allowable voltage value that can be entered is 0 01 V and the maxim
3. Fight Channel Strain Completion amp Excitation Signal Conditioning Plug on VT1506A VT1507A M User s Manual The VT1506A VT1507A manual also applies to Agilent HP E1413Bs as Agilent HP E1413 Options 16 17 Enclosed is the User s Manual for the VT1506A VT1507A Signal Conditioning Plug ons Insert this manual in your VT1413C Agilent HP E1313 or VT1415A manual behind the Signal Conditioning Plug ons divider VXI Technology Copyright VXI Technology Inc 2003 Manual Part Number 82 0081 000 Printed J uly 1 2003 Printed in U S A VT1506A VT1507A Fight Channel Strain Completion and Excitation Signal Conditioning Plug on Introduction VT1506A and VT1507A are Signal Conditioning Plug ons SCPs that provide the Strain Completion and Excitation Voltages for strain measurements 1506 is for 120 bridges and HP E1507 for 350 bridges The SCPs provide Strain Completion and Excitation Voltages for a total of 8 channels About This Manual Except where noted all references to the VT1413C apply to the VT1415A and Agilent HP E1313 This manual shows how to connect to the Terminal Module for strain measurements and also shows how to control the Signal Conditioning Plug on SCP using SCPI commands and Register Based commands The following also explains the capabilities of the SCP and gives the specifications The manual contents consist of How The VT1413C Makes
4. 366 uV Tempco 39 difference between factory calibration and CAL temp Completion Resistors Power 0 125 W 125 Tolerance 0 05 TCR 5 ppm C Bridge Offsets 41 C of tare cal 1 4 Bridge Offset 40 uV Note Offset may vary depending on the stability of the attached strain gage Strain Accuracies for System Gain Offset Error 40 ue Noise Error 27 ue A D Filter Off 20 ue A D Filter On The graphs on the following pages shows the following strain accuracies Quarter Bridge 1 4 Bridge Half Bridge 1 2 Bridge Bending Half Bridge 1 2 Bridge Poisson Full Bridge Bending Full Bridge Poisson Full Bridge Bending Poisson Spedfications VT1506A 07A Strain SCP 21 00705 000 00 05 gol x ums 7 9 95 TAM 1 gt bia rela amd Up l7 een Pe J 4 4 1 1 n 25 9 L VEOS ELA ERN i NS edant or aed ec iure in get 440 L KO YEDSLLA WW MERE 330 29114 2 1490 vZOS AARORARREREFFTESET C ARAJARSRSRARSERAR re 330 100 v LOS ELA 0009017 ONE 9 01 X uiis Spedfications VT1506A 07A Strain SCP 22 OIX WIENS 440 12115 pox ido vEOSLLA 4 5 lt 440
5. BLOCK FOR CH 32 63 SCP 5 7 SCP 6 Fez lalla ht T Tesla r SX c LS 1391 95 E E 188 E 188 LHHL LHHL LHHL LHH L LHHL LHHL LHH Figure 7 VT1506A 07A B Size Terminal Module Connections Ch 32 63 SCP2 SCP 1 SCP 3 E SCP 4 SCP6 LL HH WW E 33 32 W E 3332 HH 10 11 WE 12 13 2627 LE 28 29 35 34 5150 E mEn 08 09 E 2425 En 3736 E 39 3815352 E 55 54 HH HH HH HH H H HH 1 _ Figure 8 Agilent HP E1413 Option 16 17 Terminal Module Connections 6 VT1506A 07A Strain SCP Connecting To The Terminal Module Typical Location of Figure 9 shows where to connect the strain gages to the Terminal Module The Terminal Module _ figure assumes that the Strain Completion and Excitation SCP is the first SCP nections 1 SCP 0 and the Direct Input SCP is the
6. 4 Strain 1 1 Shunt Gage E 3500 2kQ 1 l 1 1 4 m 1 p 4 3 Jumper I 1 1 rd 1 CREAR E E 1 E e g Direct Input SCP M und E MM oii H a gt To L VT1413C Qt Agilent HP E1313 1 I Figure 2 Typical 1 2 Bridge Strain Gage Measurement Terminal Module Completion Excitation Riana eas aie naa an 1 Et Excitation Jumper 24 4 eo i 1 Strain Strain 01 H 1 Gage 27 Gage 2 L 2 it io 1 1 Excitation VOW Voltage 1 Q 1 W or 29 4 Strain Strain 1 pog 3500 Shunt Gage Fog 2kQ 414 Bridge pog Jumper O NE i Fog We a eU Ic EUIS 1 1 cr E C EC 1 H t To L VT1413C QA Agilent HP E1313 i 1 fot Figure 3 Typical Full Bridge Strain Gage Measurement How The VT1413C Makes Strain Measurements VT1506A 07A Strain SCP 3 Selecting The 1 4 Bridge Jumper Remove the 1 4 Bridge Jumper of any channel that is to make a 1 2 Bridge Full Bridge measurement Figure 4 shows the l
7. Bridge Jumper s for all channels that are to make Full Bridge measurements if jumper s is installed see Figure 4 Strain Excitation SCP 0 Top Sample Direct Input SCP 1 HLG DGHLGHLGHLGHLGHLGHLG Og e cquo eq su e Shield Bottom Sample Bending Full Bridge Strain Excitation SCP 0 VW Q NO a O C H H L LHHL LHHL LHHI Direct Input SCP 1 HLGQOGHLGHLGHLGHLGHI pgs hogs age GHLQG JC 45J Poisson Full Bridge Figure 12 Full Bridge Connections 10 VT1506A 07A Strain SCP Conneding To The Terminal Module Strain Excitation SCP 0 VW stu OR O OOL nf LHHL LHHI Direct Input SCP 1 GO OGCHLGHLGHLGHLGHLGHLG Log LogJ 10 L444 L 424 135 L 147 L454 O 222222222222272 G Bending Poisson Full Bridge Bottom Sample enm e Shield NN c ee Figure 13 Full Bridge Connections Cont VT1506A 07A Strain SC
8. Strain Measurements 2 Selecting The 1 4 Bridge 4 Connecting To The Terminal Module 5 Programming With SCPI 12 Using External Excitation 16 Using Shunt Resistor 18 Register Based 20 Specifications dre whe 21 Installation Notice that the VT1506A 07A has several jumpers that must be set before installing itin its V XI module See Figures 4 14 and 15 for jumper location and function Introduction VT1506A 07A Strain SCP 1 How VT1413C Makes Strain Measurements The VT1413C requires two SCPs to make strain gage measurements One SCP provides the Excitation Signals and Bridge Connections i e the VT1506A 07A SCP and the other SCP the sense SCP makes the measurement connections to the VT1413C e g VT1501A Direct Input SCP Figures 1 2 and 3 show examples of a typical 1 4 Bridge 1 2 Bridge and Full Bridge strain gage measurement respectively In the figures the Strain Completion and Excitation SCP supplies the strain completion circuitry for the 1 4 and 1 2 Bridge configurations and the excitation voltage for all the bridge configurations The 1 4 Bridge Jumper must be installed for 1 4 Bridge measurements and removed for 1 2 and Full Bridge measurement
9. for Agilent HP 1506 07 SCPs The connections are shown in Figure 6 and 7 For Agilent HP E1413B and below Terminal Modules use stickers for Agilent HP E1413 Option 15 16 SCPs The connections are shown in Figure 8 i VT1506A 07A E Ground jumpers al Y round Guard To Groun terminals to 9 mE NOTE Yous wil short the Wagner Voltage om c channels Jum o Bud VW VW C H Seale ST 1 1346 L LHHL L LHHL E B E 34 gg tg 38 LEJ By gya H E VW VW N 0 L T 1 n Pes Teal rin Ot 1 CH sal ELT NN E LHHL LHHL LHHL LHHL 0 Oh LHHLE LHHLEZLHHL
10. second SCP 1 SCP 1 8 E amp E x 5 LA gt i 15 5 1 Ue LE Mes Mb Connections Excitation o pu SET 59 rE 85 L LHHL LHHL LHHL Direct Input SCP supplies the measuring path to the A D GHLGHLGHLGHL L45 Figure 9 Typical Locations of Terminal Module Connections Conneding To The Terminal Module VT1506A 07A Strain SCP 7 Wiring the Terminal See Attaching and Wiring the Terminal Module in the VT1413C Module User s Manual to wire the strain gages to the Terminal Module For accurate measurements use a twisted shielded cable for the strain gage connections Connect the shield to the specimen and to the guard G terminal on the Terminal Module Note The following figures in this section show the connections using SCP 0 as the Strain SCP and SCP 1 as the Direct Input SCP Use the same technique using other SCPs and other channel numbers For example for a Channel 00 H and L connection on SCP 0 connect to H and L on Channel 57 for SCP 7 1 4 Bridge Use Figure 10 for 1 4 Bridge connections to the Terminal Module nstall the Connections 4 Bridge Jumper s for all channels that are to make 1 4 Bridge measurements if jumper s is removed see Figure 4 Strain Excitation SCP 0 10 Qr e Ce
11. 0 oe a PR ahaa ae SCP 0 al 02 3 Direct Input SCP 1 GHLGHLGHLGHLGHL G Log J Logi C492 11 4 143404441464 Shielded Cable Shield Figure 10 Typical 1 4 Bridge Connections 8 VT1506A 07A Strain SCP Connecting To The Terminal Module 1 2 ridge Use Figure 11 for 1 2 Bridge connections to the Terminal Module Remove the Connections 4 Bridge Jumper s for all channels that are to make 1 2 Bridge measurements if jumper s is installed see Figure 4 Strain Excitation SCP 0 Q Direct Input SCP 1 a Hl HI GHLGHLGHLGHLGHL pe poe hae Pa Sample 62 _ E s E 7 Shield Bending 1 2 Bridge Bottom 24 9 Strain Excitation SCP 0 EET CE3 fey OOo QOL HOO HHL LHHL LHHI Direct Input SCP 1 HLGQOOGHLGHLGHLGHLGHLGHLG F ge epo Sete oig e s ia eqs C Q Q 0 Poisson 1 2 Bridge Figure 11 Typical 1 2 Bridge Connections Conneding To The Terminal Module VT1506A 07A Strain SCP 9 Full Bridge Use Figure 12 and 13 for Full Bridge connections to the Terminal Module Connections Remove 1 4
12. AL TARE operation is returned STR GFAC 2 9108 115 specifies the gage factor on sense channels 8 15 selected factor is 2 default value STR POIS 9108 115 set Poisson ratio for EU conversion selected value is 3 default value FUNC STR FBP 1 108 115 link channel 8 15 to EU conversion for strain measurement selected voltage range is 1 V When the bridge is in the Strained configuration and measurement are to be made use the VT1413C s INITiate and TRIGger commands to make the strain measurements You must define what triggers etc to use to make the measurements see the VT1413C User s Manual for information The following explains the commands used in strain measurements The following explains the commands that link the strain EU conversion with the specified channels The commands tell the VT1413C to use the EU conversion for strain measurements The VT1413C performs the appropriate EU conversion e g 1 4 Bridge measurements depending on the command used Thus each bridge configuration has its own command with the command used for the 1 4 Bridge configuration as the default value See Linking Channels with EU Conversion in Chapter 3 ofthe VT1413C User s Manual The syntax of a typical command is SENse FUNCtion STRain HBENding range ch list where range is the voltage range of the VT1413C default value or no specified parameter is AUTO and ch list specifies the channels of the
13. EZLHHL LrLSLHHLcSLHHLCSLHHLC SEL RR 5 88 88 LERS gt 83 58 E 885 VW i 5 Figure 5 VT1506A 07A C Size Terminal Module Connections Conneding To The Terminal Module VT1506A 07A Strain SCP 5 m RAT 168 L LHHL LHHL LHHL LHH re 85 El 88 pl 381 rg 85 LH HL LHHL LHHL LH SCP 0 LILILILI Epp qus SCP 3 US HTS LT GND LCALHCAL LO HI 5g 2 oc OHMS ERA O DO USE CENTER BLOCK FOR CH 32 63 SCP 1 SCP2 NW a rel 8811 ISS nO 138 uw m e 48 T ces 188 LHHL LHHL LHHL LHHI j L L HHL LHHL LHHL LHH L 1 Figure 6 VT1506A 07A B Size Terminal Module Connections Ch 00 31 FT res 129 L LHHL LHHL LHHL LHH VW 1881 e138 1851 88 LHHL LHHL LHHL LHH SCP 4 SCP 7 O DO NOT USE CENTER
14. P Eb HO YEDSLLA 440 4 ZL 190 VZOSLLA eee ces 9 B9 POTP9PTS TUSOPB AAO 19114 EL 00 VLOSELA prverr rr Ee edd 00 Q0 t fie pier TEST 00 1 9 01 durpuagq IMA VT1506A 07A Strain SCP 25 Spedfications 01 X HENS J40 WA CT EdO dH we 4 ke i m 8x 1 140 THO 1914 21 140 20519 dH ee a ee JJO 114140 TOSTA dH GOOF 0005 000 oe _ Hn 01085104 IsPLIg o pi 004I 009 Jam a eem DHT gt DU tI DUO cl OO TT Yaf 000 OQ 8 00 9 00 s 007 0077 001 0 01 X urls Spedfications VT1506A 07A Strain SCP 26 00 05 00702 000 ovoz 900 01 x ureng 0077 1 m 19113 v9x CEL r BE inesse 208A X EL VEOSLLA 007 23029114 ZL WO vZOS ELA 530 21914 HO v LOSLLA 9 01 X 1055104 gurpuag VT1506A 07A Strain SCP 27 Spedfications
15. P Excitation Voltage Activation VT1506A 07A Only Excitation Calibration Register XXX Don t Care ppp Plug on ccc SCP channel To query an SCP for its ID value write the following value to Parameter Register 0 SCP number x 40 Then write the opcode for SCPREAD 0800 6 to the Command Register The ID value will be written to the Response Register Read the Response Register for the value After the VT1506A 07A is reset or after a power on condition the SCP s excitation voltage is not enabled This is only for the VT1506A 07A and not the Agilent HP E1413 Options 16 17 To enable the excitation voltage write a 1 to Register 2 The excitation calibration register controls a DAC that adjusts the SCP s internal excitation voltage for 3 9 V The Register Based command CARDCAL 100016 controls this register and the user should not write to them 20 VT1506A 07A Strain SCP Register Based Programming Specifications General Specification Strain Measurement Accuracies SCP Current Requirements Amps 5 5 24 24 Vmax 24 24 1506 0 28 0 28 0 026 0 032 0 023 0 027 1507 0 09 0 09 0 026 0 032 0 023 0 027 Excitation Voltage measured with VT1501A Direct Input Accuracy 90 day 23 1 with CAL done after 1 hr warmup 3 9000 V nominal 512 uV Noise 3 sigma 350 O completion one channel 3 90 V A D Filter Off 450 uV A D Filter On
16. P 11 Conneding To The Terminal Module Programming With SCPI Commands Configuring the ID of the SCP The following SCPI commands verify the SCP types installed in theVT1413C and how to program the VT1413C for strain measurements using the VT1506A 07A SCPs The commands listed in this section are also shown in Chapter 5 of the VT1413C User s Manual A configuration jumper must be installed when the VT1506A 07A is to be used in Agilent HP E1413A B Scanning A D modules This jumper must be removed when the VT1506A 07A is to be used VT1413C and Agilent HP E1313A Scanning A D modules or in VT1415A Algorithmic Controller modules See Figure 14 for jumper location Board Oriented With Connectors Down Checking the ID of the SCP Jumper installed for Jumper removed for use in use in Agilent HP E1413A B VT1413C VT1415A and Agilent HP E1313A Figure 14 SCP ID Select Jumper After configuring the ID Select jumper use the SYSTem CTY Pe lt channel gt command to verify SCP type s in the VT1413C The channel parameter specifies a single channel in the channel range covered by the SCP of interest The first channel numbers for each of the eight SCP positions are 0 8 16 24 32 40 48 and 56 The value returned for the VT1506A SCP in an Agilent HP E1413A B is HEWLETT PACKARD E1413 Opt 16 120 Ohm Strain Bridge Completion SCP 0 0 12 VT1506A 07A Strain SCP Progra
17. mming With SCPI Commands The value returned for the VT1506A SCP in a 1413 1415 or an Agilent HP E1313A E14154A is HEWLETT PACKARD E1506 120 Ohm Strain Bridge Completion SCP 0 0 The value returned for the VT1507A SCP in an Agilent HP E1413A B is HEWLETT PACKARD E1413 Opt 17 350 Ohm Strain Bridge Completion SCP 0 0 The value returned for the VT1507A SCP in a VT1413C VTI415A or an Agilnet HP E1313A is HEWLETT PACKARD E1507 350 Ohm Strain Bridge Completion SCP 0 0 To determine the type of SCP installed on channels 0 through 7 send SYST CTYP 100 query SCP type 0 enter statement here enter response string Maki ng 1 4B ridge The following example shows how to make 1 4 Bridge measurements The example Measurements ses a Strain Completion and Excitation SCP VT1506A or VT1507A for the source and a Direct Input SCP VT1501A for the sense The source channels 0 through 7 are set for 1 4 Bridge configuration 1 4 Bridge Jumper installed The sense channels are 8 through 15 Bridge is Unstrained following specifies the parameters to convert strain gage readings for the specified sense channels Do the following when the bridge is in the Unstrained configuration CAL TARE 108 115 measure the unstrained voltage on sense channels 8 15 CAL TARE to return the success flag from the CAL TARE operation enter CAL TARE query wait until success flag from CAL TARE operation is returned STR GFAC 2 108 115 s
18. ocation of the jumpers on the connector side of the board The figure shows a removed jumper on channel 7 for a 1 2 or Full Bridge measurement and installed jumpers on channels 0 through 6 for 1 4 Bridge measurements default setting Note Be sure to keep any removed jumpers for future use in case 1 4 Bridge measurements are to be made later Board Oriented With Connectors Down Jumpers Installed for 1 4 Bridge Measurements Channels Jumper Removed for Full or 1 2 Bridge Measurements Figure 4 Location of the 1 4 Bridge Jumper 4 VT1506A 07A Strain SCP Selecting The 1 4 Bridge umper Connecting Terminal Module This section shows how to make 1 4 1 2 and Full Bridge strain gage connections to the Terminal Module The Terminal Module supplies the connections between the external strain gages and both the Strain Completion Excitation SCP and the sense SCP e g Direct Input SCP Connections on the The SCP connections for the the Terminal Modules are shown on the stick on Terminal Module labels that came with the SCP Use the appropriate label for the type of Terminal Module you have The connections and appropriate stickers for the different Terminal Modukes are as follows For VT1413C and above Terminal Modules use stickers for VT1506A 07A SCPs The connections are shown in Figure 5 For Agilent HP E1313 Terminal Moduless use stickers
19. on Jumper e Strain gt 01 H Gage 2kQ V 52 1 Excit ation oltage 2 1200 Strain or a Gage 7 3500 2 414 Close Bridge FET E Jumper Switch 8 e e Shown is a 1 2 Bridge configuration the function for the shunt resistor is the same for other bridges Figure 17 Adding the Shunt Resistor Using The Shunt Resistor VT1506A 07A Strain SCP 19 Register Based Programming Chapter 6 of the VT1413C User s Manual cover the Register Based commands shown below You should read that chapter to become familiar with accessing registers and executing Register Based commands This section relates those commands to the parameter values that are specified for this SCP When Register Programming an SCP most communication is through the Signal Conditioning Bus For that you will use the Register Commands SCPWRITE lt regaddr gt lt regvalue gt and SCPREAD lt regaddr gt Read returned value Write lt regvalue gt SCP Register lt regaddr gt Value SCP ID Opt 16 0 016 00ppp0000002 Opt 17 C04016 VT1506A 0 016 VT1507A C03016 SCP Gain Scale XXX016 Whole SCP Reg 1 00 0000012 SCP Excitation Whole SCP Reg 2 00ppp0000022 Activation 116 Channel Gain 046 Channel Reg 1 01 0012 Calibration 16 Whole SCP Reg 3 01ppp0000032 where nnn Cal Value Checking the ID of the SC
20. or 1 2 or Full Bridge Bending measurements The default value of the command is 0 3 The command syntax is SENse STRain POISson poisson ratio ch list where poisson ratio is the Poisson ratio default is 2 and cA list specifies the channels of the sense SCP e g VT1501A Direct Input that connects to the bridge not the Strain Completion and Excitation SCP Because of the number of possible strain gage configurations the driver must generate any Strain EU conversion tables and download them to the instrument when INITiate is executed This can cause the time to complete the INIT command to exceed 1 minute Using External Excitation Voltages Isolating the Internal Excitation Supply You can use your own external excitation voltage instead of using the internal voltage of the Bridge Completion and Excitation SCP If using an external voltage you must isolate the internal excitation supply that is on the SCP connect the external voltage to the Terminal Module enter the value of the excitation voltage into the VT1413C so it can make the correct EU conversions for strain measurements To use an external excitation voltage isolate the internal excitation supply from the bridge To do this remove the Excitation Jumpers from the Bridge Completion and Excitation SCP as shown in Figure 15 16 VT1506A 07A Strain SCP Using External Exdtation Voltages Board Oriented With Connectors Down
21. ou can use the SENSe STRain UNSTrained command to enter the unstrained voltage In this case you must measure and enter the offset voltage of the bridge when the bridge is Unstrained The command syntax is SENSe STRain UNSTrained unstrained v ch list where unstrained v is the voltage value of the bridge in the unstrained position default is 0 V and ch list specifies the channels of the sense SCP e g 1501 Direct Input that connects to the bridge not the Strain Completion and Excitation SCP The SENse STRain GFACtor command specifies the gage factor to be used by the VT1413C to calculate the strain measurements The default value of the command is a factor of 2 The command syntax is SENse STRain GFACtor gage factor 9 ch list Programming With SCPI Commands VT1506A 07A Strain SCP 15 Purpose of the Poisson Ratio Command STR POIS NOTE where gage factor is the gage factor value default is 2 and ch list specifies the channels of the sense SCP e g VT1501A Direct Input that connects to the bridge not the Strain Completion and Excitation SCP The SENse S TRain POISson command sets the Poisson ratio to be used by the VT1413C for EU conversion of strain values measured see Linking Channels with EU Conversion in Chapter 3 of the VT1413C User s Manual This command is only needed if making Poisson strain measurements It is not needed for making 1 4 Bridge
22. pecifies the gage factor on sense channels 8 15 selected factor is 2 default value FUNC STR QUAR 1 108 115 link channel 8 15 to EU conversion for strain measurement selected voltage range is 1 V Bridge is Strained When the bridge is in the Strained configuration and measurement are to be made use the VT1413C s INITiate and TRIGger commands to make the strain measurements You must define what triggers etc to use to make the measurements see the VT1413C User s Manual for information Programming With SCPI Commands VT1506A 07A Strain SCP 13 Making Full Bending Poisson Bridge Measurements Bridge is Unstrained Bridge is Strained Comments How to Link EU Conversions to Channels The following example shows how to make Full Bridge Bending Poisson Bridge measurements The example uses a Strain Completion and Excitation SCP VT1506A or VT1507A for the source and a Direct Input SCP VT1501A for the sense The source channels 0 through 7 set for Full Bridge configuration 1 4 Bridge Jumper removed The sense channels are 8 through 15 The following specifies the parameters to convert strain gage readings for the specified sense channels Do the following when the bridge is in the Unstrained configuration CAL TARE 108 115 measure the unstrained voltage on sense channels 8 15 CAL TARE to return the success flag from the CAL TARE operation enter query wait until success flag from C
23. s see Selecting The 1 4 Bridge Jumper on page 4 The 29 4 Shunt resistor checks for correct bridge operation by adding it across one leg of the bridge see Using the Shunt Resistor on page 18 The Excitation Jumper allows the selection of an internal or external Excitation Voltage see Using External Excitation Voltages on page 16 Terminal Module Completion Excitation be ee 5 jc tp EU Uds ecc 1 E Excitation Jumper ot l 1 Strain gt 01 H 11 1 Gage 1 2kQ E Cou D Excitation Hal 1200 I uu 3500 14 Bridge 1 Jumper 1 E cod e g Direct Input SCP 1 x LH zc ELE 1 1 SES H gt L VT1413C __ Agilent HP E1313 1 1 Figure 1 Typical 1 4 Bridge Strain Gage Measurement 2 VT1506A 07A Strain SCP How VT1413C Makes Strain Measurements Terminal Module Completion Excitation 1 ECCL i Excitation Jumper QA e 1 1 Strain 01 H 1 2kQ 00 1 1 1 t I i 5 2 E SE Excitation 4 i volar mH 29
24. sense VT1506A 07A Strain SCP Programming With SCPI Commands Purpose of Channel Tare Calibration CAL TARE Purpose of the Strain Gage Factor Command STR GFAC SCP e g VT15014A Direct Input that connects to the bridge not the Strain Completion and Excitation SCP The different bridge types and corresponding EU to Channels Linking commands are in the following table Bridge Type Command Full Bending Bridge SENse FUNCtion S TRain FBENding Full Bending Poisson Bridge SENse FUNCtion STRain FBPoisson Full Poisson Bridge SENse FUNCtion STRain FPOisson 1 2 Bending Bridge SENse FUNCtion STRain HBENding 1 2 Poisson Bridge SENse FUNCtion S TRain HPOisson 1 4 Bridge SENse FUNCtion S TRain QUARter The CALibration TARE command measures the voltage across the bridge to determine the unstrained voltage value of the bridge This corrects for the offset voltage across the bridge when in the Unstrained configuration The command automatically executes the CAL command and thus calibrates the internal excitation supply of the Bridge Completion and Excitation SCP The VT1413C uses the unstrained reading 1 offset voltage in conjunction with the strain gage factor see Purpose of the Strain Gage Factor Command STR GFAC below to calculate the strain measurements You normally perform both operations before making the actual strain measurements Instead of using CAL TARE y
25. um value is 42 V Using External Exdtation Voltages VT1506A 07A Strain SCP 17 Completion Excitation SCP VW 25 22 22 External Excitation Connect the External Excitation Supply to any and terminal pair Shown is a 1 4 Bridge configuration connections to other configurations is the same Figure 16 Connecting the External Excitation Supply Using The Shunt Resistor To check if the bridge is operational you can add a 29 4 Shunt resistor across one leg of the bridge as illustrated in Figure 17 A FET switch adds or removes the resistor When the resistor is added it changes the unstrained offset voltage on the bridge The resistor can only affect the bridge balance as long as you follow the connections shown in Figures 1 2 and 3 Use the OUTPut SHUNt command to add or remove the resistor from the bridge The syntax of the command is OUTPut SHUNt 1 0 OFF 18 1506 07 Strain SCP Using The Shunt Resistor where 1 or ON adds the shunt resistor and 0 or OFF default value removes the resistor Terminal Module Completion Excitation Excitati
Download Pdf Manuals
Related Search