Mitsubishi Electric MELSEC FX3U Programming Manual page 683

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
• Subtract "1" from the value of the pointer data
+n-1
S S
+n-1
S S
Related device
Device
M8020
Related instructions
Instruction
SFWR(FNC 38)
SFRD(FNC 39)
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
executed.
Check in advance using a comparison instruction whether the current value of
n-1", and then execute this instruction.
• When the current value of the pointer
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)
S
• When is smaller than "0" (error code: K6706)
S
Data area
+n-2 +6
S S
No data area
+n-2 +6
S S
Name
Zero flag
Turns ON when the instruction is executed while the pointer
Shift write [for FIFO/FILO control]
Shift read [for FIFO control]
S
S
27 Data Operation 3 – FNC210 to FNC219
27.3 FNC212 – POP / Shift Last Data Read [FILO Control]
.
S
+5 +4 +3
S S S
+5 +4 +3
S S S
→ For the zero flag use method, refer to Subsection 6.5.2.
Description
Description
is "0", the zero flag M8020 turns ON and the instruction is not
is "1", "0" is written to
S
Pointer
+2 +1
S S
In the case of K4
Pointer
+2 +1
S S
K4→K3
S is "0".
satisfies "1 ≤
S
and the zero flag M8020 turns
21
22
D
23
24
25
26
≤
S
27
28
29
30
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