Rockwell Automation T3431-CA ICS Regent Thermo Couple Input Assembly - Manual (Page 10)

Thermocouple Input Assembly (T3431)
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Industrial Control Services
Application
Simplex Configuration
Thermocouple input modules provide a suitable interface to
non-critical input signals. Although many of the circuits in
the thermocouple input module and multiplexer are
automatically tested and annunciated, some logic circuits and
most of the field-side sensing circuits are simplex and non-
tested. This simplex input configuration is illustrated in
Figure 5.
Figure 5. Simplex Thermocouple Input Configuration.
Fault Tolerant Configurations
For critical inputs, redundant input modules, multiplexers
and termination panels are used in a 2oo3 or 1oo2 fault
tolerant configuration. In these configurations the redundant
thermocouple input equipment is connected to single or
multiple thermocouples. If redundant thermocouples are
installed in the field, each thermocouple connects to one
termination panel, multiplexer and input module. These
configurations are illustrated in Figure 6, showing triple
redundant input modules. Each thermocouple input module,
cable, term panel and multiplexer is hot replaceable. In
redundant input configurations, if a fault occurs in one set of
equipment, the failed equipment can be removed and replaced