Rockwell Automation 1755-OF8 GuardPLC Controller Systems - Manual (Page 102)

102 Publication 1753-UM001C-EN-P - March 2010
Chapter 11 Pulse Testing
Consider the following when choosing a method of pulse testing:
•
The certified function block lets the pulse test source (output)
and safety input to be on different physical nodes. The OS
configured pulse test assumes that the source and input are local
to the same physical controller or I/O module.
•
The certified function block has a pulse test fault output that can
be used for status inside the user program. The OS configured
pulse test has an error code that can be monitored for pulse test
status.
•
The OS configured pulse test occurs each cycle. The pulse test
certified function blocks allow you to configure the pulse test
interval.
•
The duration of the pulse test is configurable when using the
certified function blocks.
•
The pulse test can be disabled if necessary when using the
certified function blocks.
•
The response to RPTO/SPTO pulse test faults is user
configurable.
See the Certified Function Block Safety Reference Manual, publication
1753-RM001 , for more information on the Single Pulse Test Output
(SPTO) and Redundant Pulse Test Output (RPTO) certified function
blocks.
Response to OS
Configurable Faults When the following occurs, the faulted inputs are set to 0, a fault code
is generated, and the FAULT status indicator is on:
•
Short-circuit occurs between two parallel connections.
•
Two connections are reversed.
•
Earth fault occurs on one of the lines (only with earthed
reference pole).
•
Line break or opening of the contacts (for example, when one
of the E-stop off switches is pressed in the example above), the
FAULT status indicator is on and the fault code is generated.
TIP
If multiple errors exist at the same time, the error code is the
sum of the individual error codes. See
Appendix B for error code
information.