Message Execution Timing Diagram (Rung = False) - Allen-Bradley Micro800 General Instructions Manual

Chapter 9
Communication instructions
220

Message execution timing diagram (Rung = FALSE)

The following table describes the message conditions and bit status for each
execution step identified in the timing diagram when the rung goes to FALSE
during execution.
Step Message description
1 Rung condition goes TRUE.
Message executioy is enabled.
2 Rung condition goes FALSE.
Message execution continues.
3 Message buffer is acquired.At this time, input data (that is, the "data"
parameter for write messages) is copied for transmission. Subsequent
changes to the input data will not be reflected in the transmitted message.
4 Message transmission starts.
5 Message response is received.
6 Message is scanned again after step 5.
Timing diagram for (Rung = FALSE)
Rockwell Automation Publication 2080-RM001D-EN-E - February 2015
Bit status
EN bit is set.
All other bits are cleared.
EW bit is set.
EW bit is cleared.
ST bit is set.
ST bit is cleared.
DN bit is set.
EN bit is cleared.