Mitsubishi Electronics FX1S manual 13 MPS, MRD and MPP, MPS, MRD and MPP usage

FX Series Programmable Controllers Basic Program Instructions 2

2.13MPS, MRD and MPP

FX1S FX1N FX2N FX2NC

Mnemonic	Function	Format	Devices	Program steps
MPS	Stores the current
	result of the		N/A	1
(Point Store)	internal PLC
		MPS
	operations
MRD	Reads the current
	result of the		N/A	1
(Read)	internal PLC
		MRD
	operations
MPP	Pops (recalls and
	removes) the		N/A	1
(PoP)	currently stored
		MPP
	result

Basic points to remember:

-Use these instructions to connect output coils to the left hand side of a contact.

Without these instructions connections can only be made to the right hand side of the last contact.

-MPS stores the connection point of the ladder circuit so that further coil branches can recall the value later.

-MRD recalls or reads the previously stored connection point data and forces the next contact to connect to it.

-MPP pops (recalls and removes) the stored connection point. First, it connects the next contact, then it removes the point from the temporary storage area.

-For every MPS instruction there MUST be a corresponding MPP instruction.

-The last contact or coil circuit must connect to an MPP instruction.

-At any programming step, the number of active MPS-MPP pairs must be no greater than 11.

MPS, MRD and MPP usage:

• When writing a program in ladder format, programming tools automatically add all MPS, MRD and MPP instructions at the program conversion stage. If the generated instruction program is viewed, the MPS, MRD and MPP instructions are present.

•When writing a program in instruction format, it is entirely down to the user to enter all relevant MPS, MRD and MPP instructions as required.

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