VXI VT1422A - Manual (Page 473)

VT1529A/B Verification & Calibration 471 Appendix C
Test V-6: Filters
Description
Tests the low-pass filters for each channel in the VT1529A/B. The nominal
filter bandwidths are 2 Hz, 10 Hz, 100 Hz, and 20 kHz.
The filter bandwidth is calculated by measuring the rise time of the step
response. The bandwidth is related to the rise time by the equation:
Bandwidth = 0.35 / Rise Time
The VT1422A cannot sample fast enough to measure the rise time of the
20 kHz filter. The test procedure for this filter checks that the bandwidth is
greater than 800 Hz, which is sufficient to verify that none of the other filters
are being used.
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 VT1531A Voltage Output SCP should be installed on the VT1422A.
If needed, remove another SCP so that the VT1531A can be installed.
Make the following connections between the VT1531A and the Bridge
Excitation input port on the VT1529A/B front panel. This connection table
assumes that RJ-45 terminal block for the VT1422A is being used.
See Figure 3-7, “Excitation Supply Connections”, on page 68 and
Figure 2-4, “RJ-45 Connector Module and Pin-out”, on page 41 for pin-out
information for the Bridge Excitation port on the VT1529A/B and the RJ-45
connector ports for the VT1531A.
Bridge
Excitation
Input
Bridge
Excitation
Pin
VT1531A
Output
RJ-45 connector
as labeled on
terminal block
RJ-45 pin
Ch 0-7 + 1 Ch 0 + 8 1
Ch 0-7 - 2 Ch 0 - 8 2
Gnd 3 Shield Gnd 8 or 9 Shield
Ch 8-15 + 4 Ch 1 + 9 1
Ch 8-15 - 5 Ch 1 - 9 2
Ch 16-23 + 6 Ch 2 + 8 3
Ch 16-23 - 7 Ch 2 - 8 6
Ch 24-31 + 8 Ch 3 + 9 3
Ch 24-31 - 9 Ch 3 - 9 6