VXI VT1422A - Manual (Page 40)

40 Field Wiring Chapter 2
Optional Terminal and Connector Modules
The VT1422A is comprised of the main A/D module and optionally, a
Connector or Terminal Module. The Option 001 Connector Module provides
sixteen RJ-45 jacks to allow easy connection of the VT1422A to Remote
Signal Conditioning Units (RSCUs) like the VT1529A/B Remote Strain
Conditioning Unit. Optional conventional terminal modules include a
Terminal Module with screw-clamped terminal blocks (Option 011) and
another with spring-clamped terminal blocks (Option 013).
The Spring Terminal Module and Screw Terminal Module provide:
•
Terminal connections to field wiring.
-- Allows a mix of direct field wiring with some connections to
Remote Signal Conditioning Units
•
Strain relief for the wiring bundle.
•
Reference junction temperature sensing for thermocouple
measurements.
•
Ground-to-Guard connections for each channel.
The RJ-45 Connector Module provides:
•
Easy mass terminated plug-in connection to Remote Signal
Conditioning Units.
•
Allows some direct analog or digital field wiring to be connected to
RJ-45 modular plugs that are then plugged into the Connector Module.
•
Note: Since the RJ-45 Connector Module was designed for connection
to RSCUs, it doesn’t provide an on-board isothermal reference
thermistor or connection to the VT1422A’s on-board current source.
This means that the RJ-45 Terminal Module is not suitable for direct
connection to thermocouples.
The SCPs and
Terminal Module
Each SCP includes a set of labels to map that SCP's channels to the Terminal
Module's terminal blocks. See “Installing SCPs: Step 4, Labeling” on
page 28
Terminal Module
Layout
Figures 2-4 through 2-6 show the layout and feature location of the Terminal
Modules available for the VT1422A.
WARNING When handling user wiring connected to the Terminal Module,
consider the highest voltage present accessible on any
terminal. Use only wire with an insulation rating greater than
the highest voltage which will be present on the Terminal
Module. Do not touch any circuit element connected to the
Terminal Module if any other connector to the Terminal Module
is energized to more than 30 V ac rms or 60 V dc.