Mitsubishi Electric MELSEC FX3U Programming Manual page 225

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
Cautions on using RST instruction for a jumped program, subroutine program or interrupt program
When RST instruction for a timer or counter is executed in a jumped program, subroutine program or
interrupt program, the timer or counter may be kept in the reset status and the timer or counter may be
disabled.
For details, refer to the following sections:
*1
3. Indexing
Devices used in SET and RST instructions can be indexed with index registers (V)(Z).
(State relays (S), special auxiliary relays (M), 32-bit counters, "D .b", and word devices cannot be indexed.)
Circuit program
X000
X001
*1. This function is supported only in FX
4. Bit specification of a data register (D)
A bit in data register (D) can be specified as a device used in SET or RST instruction.
Circuit program
X000
X001
*1. This function is supported only in FX
Caution
When SET and RST instructions are executed for an output relay (Y) in a same operation, the result of the
instruction located nearest the END instruction (which specifies the end of program) is output.
Errors
• When an I/O number used in SET or RST instruction does not exist due to indexing, M8316 (Non-existing
I/O specification error) turns ON.
• When the device number of a device (M, T or C) other than I/O used in SET or RST instruction does not
exist due to indexing, an operation error (error code: 6706) occurs.
List program
0000 LD
SET Y000Z0 0001 SET
0004 LD
0005 RST
RST Y000Z0
3U
*1
List program
0000 LD
SET D0.3 0001 SET
0004 LD
0005 RST
RST D0.3
3U
→ For a jumped program, refer to Subsection 8.1.1.
→ For a subroutine program, refer to Subsection 8.2.1.
→ For an interrupt program, refer to Subsection 36.2.3.
V0 to V7 and Z0 to Z7 are available for
indexing.
When a used device is an input (X) or output
X000
(Y), the value of an index register (V or Z) is
Y000Z0
X001
converted into octal, and then added.
Y000Z0
Example: When Z0 is "20", Y024 turns ON or
OFF.
/FX PLCs.
3UC
When specifying a bit in data register, input "."
after a data register (D) number, and then
input a bit number (0 to F) consecutively.
X000
Only 16-bit data registers are available.
D0.3
X001
Specify a bit number as "0, 1, 2, ... 9, A, B, ...
D0.3
F" from the least significant bit.
Example: In the example shown on the left,
when X000 turns ON once, the bit 3
of D0 turns ON. When X001 turns
ON, the bit 3 of D0 turns OFF.
/FX PLCs.
3UC
7 Basic Instruction
7.13 SET, RST
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