Rockwell Automation 1772-LV Mini-PLC - 2/15 Programmable Controller (Series B) Programming and Operations - Manual (Page 66)

Advanced Instruction Set
Chapter 6
6Ć9
Figure 6.3
MCR Programming
MCR
MCR
Start fence
When MCR zone is
false nonretentive
outputs are de-
energized
Unconditional end
fence
Function: If the start fence becomes:
True
Each rung condition controls their output instructions.
False
All non-retentive output instructions within the zone area de-energize by the
MCR zone.
NOTE: Latch/unlatch instructions should not be placed within an MCR zone,
because the MCR zone maintains retentive instructions in the last active state
when the start fence goes false.
Zone Control Logic
Symbol: -(ZCL)-
Purpose: Allows control of one or a group of outputs in more than one manner
in the same program.
Syntax: Two instructions are required (Figure 6.4):