Message Execution Process (Error); Message Execution Timing Diagram (Error) - Allen-Bradley Micro800 General Instructions Manual

Message execution process (Error)

The following table describes the message conditions and bit status for each
execution step identified in the timing diagram when an error occurs during
execution.
Step Message description
1 Rung condition goes TRUE.
Message execution is enabled.
2 Message buffer is acquired.
3 Message transmission starts.
4 Message transmission times out.
4-6 As rung condition goes FALSE.

Message execution timing diagram (Error)

The following timing diagram shows a typical pattern when an error occurs during
execution.
Rockwell Automation Publication 2080-RM001D-EN-E - February 2015
Communication instructions
Bit status
EN bit is set.
All other bits are cleared.
EW bit is set.
EW bit is cleared.
ST bit is set.
EW and ST bits do not change.
EN bit is cleared.
ER bit is set.
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