LabVIEW
®
, NI-DAQ
®
, and CVI
™
are trademarks of National Instruments Corporation. Product and company names are trademarks or trade
names of their respective companies.
321567A-01
©
Copyright 1997 National Instruments Corp. All rights reserved.
April 1997
VXI-TB-1303
32-C
HANNEL
I
SOTHERMAL
T
ERMINAL
B
LOCK
This guide describes how to install and use the VXI-TB-1303 terminal
block with a VXI-SC submodule.
Introduction
The VXI-TB-1303 terminal block is a shielded board with screw
terminals that connect to a VXI-SC submodule. The VXI-TB-1303 has
a high-accuracy thermistor cold-junction temperature sensor, and an
isothermal copper plane to minimize the temperature gradients across
the screw terminals when you measure with thermocouples.
The terminal block has 80 screw terminals for easy connection.
Thirty-two pairs of screw terminals connect to the 32 differential inputs
of the VXI-SC submodule. Four terminals labeled GND connect to the
submodule’s chassis ground pins. The AIREF, AOREF, GUARD,
OUTPUT, OUT0+, OUT0-, OUT1+, OUT1-, OUT2+, OUT2-, OUT3+,
and OUT3- terminals are reserved for use with future VXI-SC
submodules.
The VXI-TB-1303 terminal block has a pull-up resistor connected
between CH+ and +5 V and a ground-reference resistor connected
between CH- and chassis ground. This pull-up resistor helps you detect
open thermocouples by detecting saturation of the VXI-SC submodule
amplifier output. The ground-reference resistor references floating
thermocouples to ground.
