Delta AH500 - Page 188

Chapter 5 Basic Instructions
5-9
Instruction code Operand Function
MC/MCR
N
Setting/Resetting the master
control
Symbol:
MC N
：
Level of the nested
program structure
N0~N31
MCR
Explanation:
1. The instruction MCR is used to set the master control. When the instruction MC is executed,
the instructions between MC and MCR are executed as usual. When the instruction MC is OFF,
the actions of the instructions between MC and MCR are as follows.
Instruction type
Description
General-purpose timer
The timer value is reset to zero. The coil and the
contact are OFF.
Timer used in the function block
The timer value is reset to zero. The coil and the
contact are OFF.
Accumulative timer
The coil is OFF. The timer value and the state of the
contact remains the same.
Counter
The coil is OFF. The timer value and the state of the
contact remains the same.
Coils driven by OUT
All coils are OFF.
Devices driven by SET and RST
The states of the devices remain the same.
Applied instruction
All applied instructions are not executed. The
FOR/NEXT loop is still repeated N times, but the
actions of the instructions inside the FOR/NEXT loop
follow those of the instructions between MC and MR.
2. The instruction MCR is used to reset the master control, and is placed at the end of the master
control program. There should not be any contact instruction before MCR.
3. MC/MCR supports the nested program structure. There are at most 32 levels of nested
program structures (N0~N31). Please refer to the example below.