468 VT1529A/B Verification & Calibration Appendix C

where R is the completion resistor value in kΩ.With Vexcitation = 5.000 V, the nominal output voltages can be computed:for R = 0 Ω, Vsense = 0.357143 Vfor R = 120 Ω, Vsense = 0.337684 Vfor R = 350 Ω, Vsense = 0.301120 VNote 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-3.
Procedure If necessary, send the *CAL? query to the VT1422A (required if more than
eight 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

Figure C-3. Signal Path for Bridge Resistor 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