VXI VT1422A, User Manual

Page: 478 / 529

476 VT1529A/B Verification & Calibration Appendix C
Note that the actual measurements will vary based on the actual resistor
values in the dummy load, so these values should be considered approximate
when running this test.
Setup
The VT1529A/B must be connected to the VT1422A through the VT1539A
SCP. The Dummy Load must be connected to the channel(s) being tested.
The Voltage Source must be connected to the appropriate channel bank
terminals of the Bridge Excitation input on the VT1529A/B.
The signal path through the VT1529A/B is highlighted in Figure C-6.
Procedure
If necessary, send the *CAL? query to the VT1422A (required if more than
8 hours has elapsed since the last *CAL? command). The expected return
value is “+0”.
Set the Voltage Source to 2.000 V.
Configure the VT1529A/B for bending half-bridge operation using the
SENS:FUNC:STR:HBEN (@<
ch_list >) command. Disable shunt
calibration by sending the OUTP:SHUNt OFF,(@< ch_list >) command.
Send the MEAS:VOLT:UNStrained? (@< ch_list >) query to the VT1422A.
The expected return value is ~0.142 V on each channel. Now, configure for
internal shunt using OUTP:SHUNt:SOURce INTernal,(@<
ch_list >).
Figure C-6. Signal Path for Internal Shunt Test
Buffer
To VT1422A
(VT1539A SCP)
X2
Buffer
RJ-45
X2
2:1
Mux
Cal-
Cal+
8-pin Telcom
Connector (RJ-45)
Cal- Cal+
350
120
customer
10K
10K
10K
10K
+
-
Optional
Filter
2,10,100Hz
+Excitation Sense
Instrument.
Amplifier
Dynamic Strain
Output
+ Excitation
- Excitation
Internal
Rcal
50K
Local Rcal
Enable
Remote Rcal
Enable
Int/Ext Rcal
Select
Excitation Sense
from CHs 1-31
32:1
Mux
CH31
CH00
CH01
32:1
Mux
CH31
CH01
CH00
Bridge Sense
from CHs 1-31
External customer
shunt cal resistor
terminals
-R Cal
+R Cal
Current
Limit
Excitation
to CHs 1-7
enable excitation
CHs 0-7
+Excitation
+Sense
-Sense
-R Cal
+R Cal
+Excitation Sense
-Excitation Sense
-Excitation
Wagner
Voltage enable
off for full bridge
-Excitation Sense
X16
Pin 5
Pin 4
Pin 2
Pin 7
Pin 6
Pin 3
Pin 8
Pin 1
10K
Dummy Load
7.5K