Set Value Specification Method - Mitsubishi Electric MELSEC-Q Structured Programming Manual

FXCPU Structured Programming Manual
[Device & Common]
• When the coil C200 is driven by the counting input X014, the counter starts up-counting or down-counting.
When the current value of the counter increases from "-6" to "-5", the output contact turns ON. When the
current value decreases from "-5" to "-6", the output contact turns OFF.
X012
X013
X014
CC200
K-5
CS200
• The current value increases or decreases without regard to the operation of the output contact.
When the counter executes up-counting from "2,147,483,647", the count value becomes "-2,147,483,648".
In the same way, when the counter executes down-counting from "-2,147,483,648", the count value
becomes "2,147,483,647". (This type of counter is called ring counter.)
• When the reset input X013 turns ON and then the RST instruction is executed, the current value of the
counter is reset to "0" and the output contact turns OFF.
• In a latched type counter, the current value, output contact operation status and reset status of the counter
are latched (backed up) by a battery, etc. in the PLC.
• A 32-bit counter can be used as a 32-bit data register. 32-bit counters cannot be handled as target devices
in 16-bit applied instructions.
• If data beyond the set value is written to the current value register by the DMOV instruction, etc., the
counter continues counting and the contact does not change when the next counting input is received.
2.6.5

Set value specification method

1. 16-bit counter
1) Direct specification using a constant (K)
X003
2) Indirect specification using a data register (D)
X001
X003
58
M8200
RST
EN ENO
d
C200
OUT_C_32
EN ENO
CCoil
CValue
Set value (constant)
The set value can be
indirectly specified instead.
Y001
→ For details on backup methods against power interruption, refer to Section 1.2.
OUT_C
EN ENO
CCoil
CC0
K100
CValue
Constant (decimal constant)1 to 32,767
100 counts
MOV
EN ENO
s d
K100
OUT_C
EN ENO
CC0 CCoil
D5
CValue
D5:100
100 counts
Up-counting
X012
X013
X014
4 5 4
Current
3 3
2
value
1
0
When output contact has
been already turned ON.
Y001
Write in advance a value to the data register used
for indirect specification in a program, or set such
a value in advance using a digital switch.
Note that the set value of a latched (backed-up) type
D5
register can be indefinite when the battery voltage
becomes low.
2 Devices in Detail
Down-counting
2
1
0
-1
-2
-3 -4
-5
-6 -5
-6
-7 -7
-8
2.6 Counter [C]
Up-counting
0
-4 -3