Chapter 7 Second Development PlatformVP3000
283
Instruction Function
CNT 16-bit counter
Operand
C-K C0–C79, K0–K32,767
C-D C0–C79, D0–D399
Description
When CNT instruction goes from OFFON, the designated counter coil is from losing
powerreceiving power , and the current value in the counter plus 1. When the counting
reaches the setting value (current value = setting value), the contact will be:
Normally Open (NO) contact Closed
Normally Close (NC) contact Open
If there are other counting pulses input after the counting reaches its target, the contact
and current value stay intact. Use RST instruction to restart or reset the counting.
Example
Ladder diagram:
X0
C2
CNT K100
Instruction code Operation
LD X0 Load X0 (the contact A)
CNT C2 K100
C2 Counter
Setting value is K100
Instruction Function
MC / MCR The connection / disconnection between the contacts of common lists
Operand N0–N7
Description
MC instruction is master-control start instruction. When MC instruction is executed, the
execution of instructions between MC and MCR are not be interrupted. When MC
instruction is OFF, the execution of instructions between MC and MCR are:
Instruction type Description
General purpose timer
The value returns 0, the coil loses power, and no action
for the contacts
Counter
The coil loses power, the value and the contacts stay
intact
The coil driven by OUT
instruction
None receives power
Devices driven by SET and
RST instructions
Stay intact
Application instructions All disabled
MCR is the master-control end instruction that is placed in the end of the master-control
program. There should not be any contact instructions prior to MCR instruction.
MC-MCR master-control program instructions support the nested program structure (max.
8 layers) and use the instructions in the order N0–N7.
Example
Ladder diagram: (see the next page) Instruction code Operation
LD X0 Load X0 (the contact A)
MC N0
The connection of the
NO common serial
contacts
LD X1 Load X1 (the contact A)
OUT Y0 Drive Coil Y0
⁞
LD X2 Load X2 (the contact A)
MC N1
The connection of the
N1 common serial
contacts
LD X3 Load X3 (the contact A)
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