Rockwell Automation T3491 ICS Regent Multiplexed I/O Modules - Manual (Page 8)

Multiplexed I/O Module (T3491)
8
Industrial Control Services
When output data changes state, the Mux I/O module writes
the output data to both ports. At the MIU processor, the
output data is 2oo2 voted, so that when the data agrees, the
outputs are updated.
When input data disagrees, the Mux I/O module reads the
input data three more times. If the disagreement persists, a
failure is reported.
Serial Port Cable Connections
The serial communications cables are connected to the screw
terminals located on the I/O chassis directly above and below
the slot where the module is installed. Figure 4 illustrates the
proper connections for the serial ports.