Delta Electronics Extension Digital I/O Module DOP-EXIO14RAE - Manual (Page 73)

Appendix C Use of Basic Instructions|DOP-EXIO Series
C-8 Revision March, 2008, Doc. Name: 2007PDD23000014
using DCNT instruction is the same as using CNT instruction to enabling C0~C127.
2. When DCNT is Off, the counting will stop, but the existing present value in the counter will not be
cleared. To clear the present value and the contact, the user has to use the instruction RST C2XX.
Program Example:
Ladder diagram:
Instruction code: Operation:
LD M0 Loading in contact A of M0 M0
C254 DCNT K1000
DCNT C254
K1000 Set value of counter C254 as K1,000
Mnemonic Functions
MC / MCR Master Control Start / Reset
Operand N0~N7
Explanations:
1. MC is the main-control start instruction. When MC instruction is executed, the execution of
instructions between MC and MCR will not be interrupted. When MC instruction is Off, the actions
of the instructions between MC and MCR are:
Instruction type Explanation
General purpose timer
Present value = 0
Coil is Off, No action for the contact
Accumulative timer Coil is Off, present value and contact stay intact
Subroutine timer
Present value = 0
Coil is Off, No action for the contact
Counter Coil is Off, present value and contact stay intact
Coils driven by OUT
instruction
All Off
Devices driven by SET and
RST instructions
Stay intact
Application instructions
All disabled.
The FOR-NEXT nested loop will still execute back and forth for N
times.
Instructions between FOR-NEXT will act as the instructions between
MC and MCR.
2. MCR is the main-control end instruction that is placed in the end of the main-control program.
There should not be any contact instructions prior to MCR instruction.
3. MC-MCR main-control program instructions support the nested program structure (max. 8 layers)
and please use the instruction in the order N0 ~ N7.