Allen-Bradley Logix5000 Reference Manual page 162

Chapter 4 Input/Output Instructions (MSG, GSV, SSV, IOT)
Condition
Rung-condition-in is false.
(does not apply to structured text)
Examine .DN Bit
Examine .ER Bit
Rung-condition-in is true.
162
Relay Ladder Action
.EN bit = 1
.EW bit = 1
Examine .EW Bit
.EW Bit = 0
.ST bit = 1
Examine .ST Bit
.ST Bit = 0
.DN bit =
Examine .DN Bit
.DN Bit = 0
.ER Bit = 1
Examine .ER Bit
.DN Bit = 1
.DN Bit = 0
.EN bit is cleared.
.ER Bit = 1
.ER Bit = 0
The instruction executes.
The rung-condition-out is set to true.
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Structured Text Action
Examine .EN Bit
.ER Bit = 0
Block-transfer
Command
No
Execute message request.
.EW bit is set.
N/A
.EN Bit = 0
Yes
No
Module Path Valid
Yes
Module
Yes
No
Connection
Running
.ER bit is set.
Rung-condition-out is
set to false.
End