Rockwell Automation T3468A ICS Regent DC Guarded Digital Output Modules - Manual (Page 2)

DC Guarded Digital Output Modules (T3461A, 62A, 68A)
2
Industrial Control Services
Module Operation
A block diagram of a typical monitored Guarded output
module is shown in Figure 1.
The processor modules send triplicated write data commands
over the I/O Safetybus to the Guarded output module.
Onboard the Guarded output modules the triplicated data are
routed to two independent voter and I/O Safetybus logic
sections. Each section independently votes the triplicated
data and operates one of the two field effect transistor (FET)
output control switches. The two FETs are connected in series
with the load.
Figure 1. Block Diagram of a DC Guarded Output Module.
When both circuits are on, current will flow through the
output and energize a field load. If either switch is off, current
will not flow through the output and the load will be de-