Rockwell Automation T3431-CA ICS Regent Thermo Couple Input Assembly - Manual (Page 19)

Thermocouple Input Assembly (T3431)
P D - 6 0 2 4 M a r - 0 6
19
Keying
The I/O chassis can be physically keyed to prevent accidental
damage caused by inserting a module into a slot wired for a
different module type. Figure 11 illustrates how the slot keys
are installed on the I/O chassis slot field wiring connectors.
The slot key positions for the thermocouple input module is
listed in Table 3.
Figure 11. Installing Slot Keys.