Rockwell Automation 1747-SDN SLC 500 DeviceNet Scanner Module User Manual - Manual (Page 97)

Publication 1747-UM655B-EN-P - June 2007
DeviceNet Explicit Messaging 97
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Abort bit AB (word 0, bit 8) lets you abort an executing DEM
instruction by setting this bit. The ER bit will be set as soon as
the AB bit is set. This bit is reset the next time the message rung
goes from false to true.
•
Error bit ER (word 0, bit 12) is set when the message has failed
to complete successfully. This bit is reset the next time the
message rung goes from false to true. Do not set or reset this bit.
It is informational only.
•
Done bit DN (word 0, bit 13) is set when the message has
completed successfully. This bit is reset the next time the
message rung goes from false to true. Do not set or reset this bit.
It is informational only.
•
Enabled bit EN (word 0, bit 15) is set after the message rung
goes from false to true AND the module accepts this message
because it is not currently processing any other explicit
messages. (The module can process only one DEM instruction at
a time.) If the message rung goes false before the module
accepts this message, then the enable bit will remain off and the
message will not be executed. This bit is reset when the
message has completed with either the Done bit set or the Error
bit set and the message rung goes false. If the message rung
conditions remain true, you may retrigger the message
instruction by resetting this bit after either the ER or DN bit has
been set, indicating that the previous execution has completed.
•
Waiting for Slot bit WS (word 0, bit 10) is set when the message
rung goes from false to true, but the module is still processing
another DEM instruction. To be sure that this message gets
processed, you must leave the message rung conditions true
until the WS bit is reset and the EN bit is set, indicating that the
module has accepted this message for processing. Do not set or
reset this bit. It is informational only.
Done DN 13
Enabled EN 15
Waiting for slot WS 10
DEM Instruction Setup Screen Status Bits
Bit Definition Bit Mnemonic Bit Address