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FX3G/FX3U/FX3UC Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
27 Data Operation 3 – FNC210 to FNC219
27.3 FNC212 – POP / Shift Last Data Read [FILO Control]
• Subtract “1” from the value of the pointer data .
Related device
→ For the zero flag use method, refer to Subsection 6.5.2.
Related instructions
Cautions
• When this instruction is programmed in the continuous operation type, the instruction is executed in every operation
cycle. As a result, an expected operation may not be achieved.
Usually, program this instruction in the “pulse operation type”, or let this instruction be executed by a “pulsed
command contact”.
• When the current value of the pointer is “0”, the zero flag M8020 turns ON and the instruction is not
executed.
Check in advance using a comparison instruction whether the current value of satisfies “1 ≤ ≤ n-1”,
and then execute this instruction.
• When the current value of the pointer is “1”, “0” is written to and the zero flag M8020 turns ON.
Error
An operation error is caused in the following cases; The error flag M8067 turns ON, and the error code is stored in
D8067.
• When is larger than “n-1” (error code: K6706)
• When is smaller than “0” (error code: K6706)
Device Name Description
M8020 Zero flag
Turns ON when the instruction is executed while the pointer is “0”.
Instruction Description
SFWR(FNC 38) Shift write [for FIFO/FILO control]
SFRD(FNC 39) Shift read [for FIFO control]
S
Data area
Pointer
S
+n-2
S
+n-1
S
+6
S
+5
S
+3
S
+2
S
+1
S
No data area
Pointer
S
+n-2
S
+n-1
S
+6
S
+5
S
+3
S
+2
S
+1
S
D
S
+4
In the case of K4
K4
→
K3
S
+4
S
S
S
S
S
S
S
S