Master Control Instruction; Setting/Resetting The Master Control - Mitsubishi Electric MELSEC iQ-F Series Training Manual

Master Control Instruction

Setting/resetting the master control

MC, MCR
• MC: This instruction starts master control.
• MCR: This instruction ends master control.
These instructions create program with efficient ladder switching by opening/closing common buses in ladders.
Ladder using master control is illustrated below. (Left: Display on the engineering tool, Right: Actual operation)
X0
MC
N1 M0
X1 X3 M7
M5
X6 X4
X10
(1) Executed only when X0 is on
■ MC
• When the execution command of the MC instruction turns ON at the start of master control, the operation result between
the MC and MCR instructions is as per the instructions (according to ladder). When the execution command of MC
instruction turns OFF, the operation result between the MC and MCR instructions becomes as follows.
Device
Timer
Counters, retentive timers
Devices in OUT instruction
Devices in SET and RST instructions
Devices in SFT(P) instruction
Devices in basic instructions and
applied instructions
■ MCR
• This instruction indicates the end of the master control range by the master control release instruction.
• Do not prefix this instruction with NO contact instruction.
• Use these (MC and MCR) instructions with same nesting number as a pair. Note, however, that when this instruction is
nested at a single location, all master controls can be ended by just one (N) number, the smallest number.
MC
MCR
(1): Master control ladder
N1 M0
Y2
Y3
MCR
N1
Y4
Device status
The count value becomes 0, and both coils and contacts turn OFF.
Coils turn OFF but the current status of both count values and contacts is
maintained.
Forcibly turned OFF.
Current status is maintained.
(N) (d)
(1)
X0
MC
N1 M0
X1 X3 M7
M5
X6 X4
X10
55
(N) (d)
(N)
N1 M0
Y2
(1)
Y3
MCR
N1
Y4