202
FX3S/FX3G/FX3GC/FX3U/FX3UC Series
Programming Manual - Basic & Applied Instruction Edition
7 Basic Instruction
7.8 MPS, MRD, MPP
7.8 MPS, MRD, MPP
Outline
FX3G, FX3U FX3GC and FX3UC PLCs have 11 memories called "Stack" which store the intermediate result (ON or OFF)
of operations.
1. Instruction format
2. Applicable devices
Explanation of function and operation
These instructions are convenient in programming branched multi-output circuits.
1. MPS, MRD, and MPP instructions (stores the current result of the internal PLC operations, reads
the current result of the internal PLC operations, and pops (recalls and removes) the currently
stored result)
• Use MPS instruction to store the intermediate result of operation, and then drive the output Y002.
• Use MRD instruction to read the stored data, and then drive the output Y003.
MRD instruction can be programmed as many times as necessary.
• In the final output circuit, use MPP instruction instead of MRD instruction.
MPP instruction reads the stored data described above, and then resets it.
Error
MPS instruction can be used two or more times.
However, the difference between number of MPS instructions and the number of MPP instructions should be 11 or
less, and should be 0 at the end.
Instruc-
tion
Bit Devices Word Devices Others
System User Digit Specification System User
Special
Unit
Index
Con-
stant
Real
Number
Charac-
ter String
Pointer
XYMTCSD.b KnX KnY KnM KnS T C D R U\G V Z Modify K H E ""P
MPS There are no applicable devices.
MRD There are no applicable devices.
MPP There are no applicable devices.
Memory Point Store
MPS
Basic Instruction
1 step
MPS
−
Continuous
Operation
Pulse (Single)
Operation
Mnemonic Operation Condition
MRD
Memory Read
Basic Instruction
1 step
MRD
−
Continuous
Operation
Pulse (Single)
Operation
Mnemonic Operation Condition
MPP
Memory POP
Basic Instruction
1 step
MPP
−
Continuous
Operation
Pulse (Single)
Operation
Mnemonic Operation Condition
X004 X005
Y002
Y004
X006
Y003
MPS
MRD
MPP
Y005
MRD
[2]
[1]
MPP
MRD
MPS
MPP
Stack
1
2
3
10
11
0018 LD X004
0019
0020 AND X005
0021 OUT Y002
0022
0023 AND X006
0024 OUT Y003
0025
0026 OUT Y004
0027
0028 AND X007
0029 OUT Y005
0030 END
MPS
MRD
MRD
MPP
18
X007