VXI VT1422A, VT1529A/B Procedure , Troubleshooting Failures

470 VT1529A/B Verification & Calibration Appendix C
The signal path through the VT1529A/B is highlighted in Figure C-4.
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 5.000 V.
Configure the VT1529A/B for bending half-bridge operation using the
SENS:FUNC:STR:HBEN (@<ch_list>) command. This switches in the 0 Ω
resistor path. Send the MEAS:VOLT:UNStrained? (@<ch_list>) query to
the VT1422A. The expected return value is ~0.357 V on each channel.
Use the Digital Multimeter to measure the output voltage on each channel
on the Dynamic Strain Output Port. The expected value is ~11.43 V.
After measuring all channels, set the Voltage Source to 0.0 V. Send the
SOUR:VOLT:AMPL 1.0,<ch_list> command to set the offset DAC for each
channel to 1.0 V.
Use the Digital Multimeter to measure the output voltage on each channel
on the Dynamic Strain Output Port. The expected value is 1.0 V.
Troubleshooting Failures Check all connections and the Dummy Load.
Figure C-4. Signal Path for Dynamic Strain Output Port Test
Buffer
To VT1422A
(VT1539A SCP
)
X2Buffer
RJ-45
X2 2:1
Mux
Cal-
Cal+
8
-p
i
n
T
e
l
com
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
fr
o
m
C
H
s
1-
3
1
32:1
Mux
CH31
CH00
CH01
32:1
Mux
CH31
CH01
CH00
Bridge Sense
fr
o
m
C
H
s
1-
3
1
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