Mitsubishi Electronics FX1S manual Mcr, Master Control and Reset

FX Series Programmable Controllers Basic Program Instructions 2

2.14Master Control and Reset

FX1S FX1N FX2N FX2NC

Mnemonic Function Format Devices Program steps

					Y, M (no special
MC	Denotes the start				M coils allowed)
(Master	of a master control				N denotes the	3
		MC	N
Control)	block				nest level (N0 to
					N7)
MCR	Denotes the end of				N denotes the
(Master	a master control	MCR		N	nest level (N0 to	2
Control Reset)	block				N7) to be reset.

Program example:

N0

X0

MC N0 M100

M100

X1

Y0

X2

Y1

MCR N0

0	LD	X	0
1	MC	N	0
	SP	M 100
4	LD	X	1
5	OUT	Y	0
6	LD	X	2
7	OUT	Y	1
8	MCR	N	0

Note: SP - space key

N - nest level of MC (N0 to N7)

Basic points to remember:

-After the execution of an MC instruction, the bus line (LD, LDI point) shifts to a point after the MC instruction. An MCR instruction returns this to the original bus line.

-The MC instruction also includes a nest level pointer N. Nest levels are from the range N0 to N7 (8 points). The top nest level is ‘0’ and the deepest is ‘7’.

-The MCR instruction resets each nest level. When a nest level is reset, it also resets ALL deeper nest levels. For example, MCR N5 resets nest levels 5 to 7.

-When input X0=ON, all instructions between the MC and the MCR instruction execute.

-When input X0=OFF, none of the instruction between the MC and MCR instruction execute; this resets all devices except for retentive timers, counters and devices driven by SET/RST instructions.

-The MC instruction can be used as many times as necessary, by changing the device number Y and M. Using the same device number twice is processed as a double coil (see section 2.5.2). Nest levels can be duplicated but when the nest level resets, ALL occurrences of that level reset and not just the one specified in the local MC.

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