User Manual User Manual

28 Rockwell Automation Publication 440G-UM001A-EN-P — November 2013
Chapter 4 Description of Operation
OSSD Output Test Pulses
The Guardmaster 440G-LZ guard locking switch uses test pulses to check
for OSSD output faults. This process is illustrated graphically as follows:
Auxiliary/Manual Release
Safety A
Safety B
Occurs every 25 ms
Occurs every 25 ms
Occurs every 11 sec
300 μs
300 μs
˂ 600 μs
˂ 600 μs
Occurs every 11 sec
The manual release is provided to allow you to
unlock the guard door in the event of
unforeseen and uncommon circumstances.
If power is supplied to the switch and the latter
is in its locked state, invoking the auxiliary
release will cause the switch to enter a fault
condition (blinking red LED).
To reset the switch, simply cycle the power.
< 2.5 (0.098) dia.