Allen-Bradley Logix5000

420 Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Chapter 9 Array (File)/Shift Instructions (BSL, BSR, FFL, FFU, LFL, LFU)
Postscan The rung-condition-out is set to false.
Condition Relay Ladder Action
Rung-condition-in is true.
End
Examine .EU bit.
.EU = 0
.EU = 1
.EU bit is set.
.LEN < 0
Yes
No
.POS < 0
Yes
No
.EM bit is set.
.DN is set.
.EM bit is cleared.
.DN is cleared.
.LEN > Size
Of Array
Yes
No
Major Fault
.POS ≤ 1
Yes
No
.EM bit is set.
.LEN < 0
Yes
No
.POS < 0
Yes
No
.EM bit is cleared.
.DN is cleared.
.POS = 0
Yes
No
.EM bit is set.
.POS ≥ .LEN
Yes
No
.DN bit is set.
.EM bit is set.
.DN is set.
.POS < 1
Yes
No
Destination = 0
.POS = .POS -1
Destination = FIFO[0]
i = 1
FIFO[i - 1] = FIFO[i]
i = i +1
i < .LEN
Yes
No
Rung-condition-out is set
to true.