Mitsubishi Electronics FX3G User Manual
103
FX
3S
/FX
3G
/FX
3GC
/FX
3U
/FX
3UC
Series
Programming Manual - Basic & Applied Instruction Edition
4 Devices in Detail
4.6 Counter [C]
1
Introdu
ction
2
Ov
ervi
ew
ew
3
Instruction
Li
st
4
D
evices
in Det
ai
l
5
Specifi
ed the
De
vice
&
C
onst
ant
ant
6
Bef
ore
ore
Pr
og
ra
mmi
ng
ng
7
Bas
ic
ic
Instruction
8
FN
C00-FN
C00-FN
C0
9
Program Fl
ow
9
FNC
10-FN
C19
Mov
e & Com
e & Com
pare
10
FNC
20-FNC
29
Arith. & Lo
gi
c
Operati
on
4.6.3
Related devices (to specify counting direction) [32-bit counter]
When an auxiliary relay for switching the counting direction is set to ON, the counter executes down-counting, and
when set to OFF, the counter executes up-counting.
when set to OFF, the counter executes up-counting.
4.6.4
Functions and operation examples
1. General type and latched (battery backed) type 16-bit up counters
• The valid set range of 16-bit binary up counter is from K1 to K32767 (decimal constant).
K0 provides the same operation as K1, and the output contact turns on at the first counting.
• In general type counters, the counter value is cleared when the PLC turns off. In latch type counters, however, the
counter value just before power failure is stored (backed up by the battery); The counter value in the subsequent
operations can be added to the last counter value.
operations can be added to the last counter value.
• Every time the coil C0 is driven by the counting input X011, the current value of the counter increases. When a coil
instruction is executed 10 times, the output contact turns on.
After that, the current value of the counter does not change even if the counting input X011 turns on after that.
When the RST input X010 turns ON and then RST instruction is executed, the current value of the counter is reset
to "0" and the output contact returns.
After that, the current value of the counter does not change even if the counting input X011 turns on after that.
When the RST input X010 turns ON and then RST instruction is executed, the current value of the counter is reset
to "0" and the output contact returns.
• The counter set value can be set by a constant (K) as shown above, or indirectly specified by a data register
number. For example, when D10 is specified and the contents of D10 are "123", it is equivalent to "K123".
• If data beyond the set value is written to the current value register by MOV instruction, etc., the OUT coil turns ON
and the current value register becomes the set value when the next counting input is received.
• For latched (battery backed) type counters, the current value, output contact operation and reset status are backed
up against power failure.
In FX
In FX
3U
/FX
3UC
PLCs, latched type counters are backed up by the battery built into the PLC.
In FX
3S
/FX
3G
/FX
3GC
PLCs, latched type counters are backed up by the EEPROM built into the PLC.
→ For details on backup methods against power failure, refer to Section 2.6.
Counter No.
Counting
direction
switching
relay
Counter No.
Counting
direction
switching
relay
Counter No.
Counting
direction
switching
relay
Counter No.
Counting
direction
switching
relay
C200
M8200
C209
M8209
C218
M8218
C227
M8227
C201
M8201
C210
M8210
C219
M8219
C228
M8228
C202
M8202
C211
M8211
C220
M8220
C229
M8229
C203
M8203
C212
M8212
C221
M8221
C230
M8230
C204
M8204
C213
M8213
C222
M8222
C231
M8231
C205
M8205
C214
M8214
C223
M8223
C232
M8232
C206
M8206
C215
M8215
C224
M8224
C233
M8233
C207
M8207
C216
M8216
C225
M8225
C234
M8234
C208
M8208
C217
M8217
C226
M8226
X010
RST
C 0
X011
C 0
C 0
Y000
K10
Set value (constant)
It can be specified
indirectly also.
0
1
2
3
4
5
6
7
8
9
10
X010
X011
Current
value
Y000