446 Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Chapter 10 Sequencer Instructions (SQI, SQO, SQL)
Postscan The rung-condition-out is set to false.
Condition Relay Ladder Action
Rung-condition-in is true.
.LEN ≤ 0 or
.POS < 0
No
Yes
.DN bit is set.
.POS = .LEN
No
Yes
examine .EN bit
.EN = 0
.EN = 1
.EN bit is set.
.ER bit is cleared.
.DN bit is set.
.POS ≥ .LEN
Yes
No
.POS = .POS + 1
.POS Value
Rolls Over
Yes
No
.ER bit is set.
end
Rung-condition-out is set
to true.
.DN bit is set.
.POS = .LEN
Yes
No
.POS > .LEN
No
Yes
.POS = 1
Goto
Error
Error
.LEN > size of
array
Yes
No
Array[control.POS] = Source
Major Fault