Rockwell Automation Allen-Bradley 1734-IB8S, User Manual

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40 Rockwell Automation Publication 1734-UM013J-EN-P - July 2014
Chapter 2 Safety Inputs, Safety Outputs, and Safety Data
Safety Output Fault Recovery
If a fault is detected, the safety outputs are switched off and remain in the off
state. Follow this procedure to activate the safety output data again.
1. Remove the cause of the error.
2. Command the safety output (or safety outputs) into the safe state.
3. Allow the output-error latch time to elapse.
After these steps are completed, the I/O indicator (red) turns off.
The output data can now be controlled.
Muting Lamp Operation
(1734-IB8S) Beginning with firmware revision 1.002, the operation of the muting status bits
for the test outputs T1 and T3 has changed. Test outputs T1 and T3 are
controlled by your PLC processor program to illuminate a muting lamp. Muting
lamp status is monitored with a test that runs periodically during every test
interval to detect a burned-out lamp. The test runs repeatedly when the test
output is commanded on. The figure below explains how muting lamp operation,
status, and fault detection are monitored.
IMPORTANT Stuck high faults require a module power reset to clear the error.
TIP
The lamp test interval is 3 seconds. Two consecutive failed lamp tests are
required to declare a burned-out lamp condition. The lamp test may not run
immediately after the test output is energized. It starts at the next 3-second
interval. To allow time for two consecutive test intervals, program a minimum
Test Output On Time of 6 seconds.