Mitsubishi Electric FX3G SERIES Programming Manual page 216

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
Explanation of function and operation
SET instruction drives the coil for an output relay (Y), auxiliary relay (M), state relay (S) and bit specification of data
register (D).
1. When using a bit device
SET instructions located in parallel can be used consecutively as many times as necessary.
In the program example shown below, "RST Y000" after "SET Y000" corresponds to this usage.
Circuit program
X000
X001
2. When using a word device (timer or counter)
Use RST instruction to reset a counter or retentive type timer.
1) Program example of an internal counter
X010
X011
C 0
2) Program example of a high-speed counter
X010
X011
X012
C
As a contact driving the counting coil of a high-speed counter, program a contact which is normally ON when
high-speed counting is executed.
If an input relay (X000 to X005) assigned for high-speed counters is used for driving the counting coil, accurate
counting cannot be achieved.
214
SET Y000
RST Y000
RST C 0
K10
C 0
Y000
Counting direction
M8
Sequence reset
circuit
RST C
Counting coil
C
K or D
Y002
List program Timing chart
X000
0 LD X000
1 SET Y000
X001
2 LD X001
3 RST Y000
Y000
C0 up-counts the number of times X011 turns from OFF to ON.
When the counting result reaches the set value K10, the output
contact C0 is activated. Even if X011 changes from OFF to ON after
that, the current value of the counter remains unchanged and the
output contact remains activated.
For clearing the counter and returning the output contact, X010 is set
to ON.
It is necessary to specify a constant K or data register number for
indirect specification after OUT C instruction.
In the case of latched (battery backed) type counters, the current
value and the operation status/reset status of the output contact are
latched even after power failure.
For 1-phase 1-input counters C235 to C245, use special auxiliary
relays M8235 to M8245 for specifying the counting direction.
X010 in ON status: Specifies down counting.
X010 in OFF status: Specifies up counting.
When X011 turns ON, the output contact of the counter C
returned and the current value of the counter C
In counters with reset input (C241, C242 ...), the same situation is
achieved by interrupt operation when the corresponding reset input
turns ON, but any program is not required for this operation.
When X012 turns ON, turning ON/OFF of a counting input X000 to
X005 determined according to the counter number is counted.
In counters having start input (C244, C245 ...), counting is started
only after the corresponding input turns ON.
When the current value of a counter increases and reaches the set
value (K or contents of D), the output contact is set. When the
current value decreases and reaches the set value, the output
contact is reset.
7 Basic Instruction
ON
ON
ON
SET RST
instruction instruction
7.13 SET, RST
is
is reset to "0".