Mitsubishi Electronics fx3u User Manual
646
FX
3S
/FX
3G
/FX
3GC
/FX
3U
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3UC
Series
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”.
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
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.
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