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Publication SAFETY-AT017B-EN-P – July 2011
Safety Input Interlock Rung
This rung includes the safety device input interlocks, with tag names
Sts_Zone1_EStop_InputOK and Sts_Zone1_GateSwitch_InputOK, that
energize the Sts_Zone1_InputsOK OTE instruction. These interlock tags
are driven by the individual safety device input logic rungs shown
earlier. The Sts_Zone1_InputsOK tag is then included in the Output
Enable Rung which drives the ROUT instruction.
Output Enable Rung
This rung provides the operator action required to reset or enable the
safety zone output. The operator action is a HI transition of
Cmd_Zone1_SafetyReset. It latches the output enable until either a
demand is placed on a safety input, there is an input channel or output
channel fault, or a feedback fault on the output circuit. The
Sts_Zone1_InputsOK will go LO in the event of a demand on any safety
input(s) or fault on any safety input channel(s) within the zone.
The CombinedOutputStatus will go LO if any output channel on the
1791ES Guard I/O module faults or there is a connection timeout to the
I/O module. The .FP feedback fault present drops out the output enable
in the event of a feedback fault, so that reset or enable cannot occur
without operator action.
