Rockwell Automation 1746-NT4 SLC 500 Thermocouple/mV Input Module Installation Instructions - Manual (Page 5)

SLC™ 500 4-Channel Thermocouple/mV Input Module 5
Publication 1746-IN010D-EN-P - June 2004
Overview
The thermocouple/mV input module receives and stores digitally converted
thermocouple and/or millivolt (mV) analog data into its image table for retrieval by
all fixed and modular SLC 500 processors. The module supports connections from
any combination of up to four thermocouple or mV analog sensors. See the input
specifications beginning on page 21 for thermocouple types, their associated
temperature ranges, and the analog input signal ranges that each 1747-NT4 channel
will support. Each input channel is individually configurable via software for a
specific input device and provides open-circuit, over-range, and under-range
detection and indication.
The module contains a removable terminal block with two cold-junction
compensation (CJC) sensors. There are no output channels on the module.
Configuration is done via the user program. There are no DIP switches.
Channel Status LEDs
Channel status LEDs indicate the status for channels 0 through 3. Related error
information is contained in the channel status word. This includes conditions such
as:
• normal operation
• channel-related configuration errors
• open-circuit errors
• out-of-range errors
All channel errors are recoverable errors.
Module Status LED
The module status LED shows diagnostic or operating errors related to the module.
These non-recoverable errors may be detected during power-up or during
operation. Once an error has been detected, the module no longer communicates
with the SLC processor. Channel states are disabled, and data words are cleared (0).
Failure of any diagnostic test results in a non-recoverable error and requires the
assistance of your local Allen-Bradley distributor or Rockwell Automation
representative.