Mitsubishi Electric QD62, User Manual

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6 - 8 6 - 8
MELSEC-Q
6 CONVENIENT USAGE
Number Description
1)
The present counter value of 0 is stored in the present periodic pulse count
value storage buffer memory {addresses 12
H
to 13
H
(32
H
to 33
H
)} (hereinafter
called the present value buffer memory).
2)
The present counter value of 200 is stored in the present value buffer memory.
The value 0 that has been stored in the present value buffer memory will be
stored in the previous periodic pulse count value storage buffer memory
{addresses 10
H
to 11
H
(30
H
to 31
H
)} (hereinafter called the previous value buffer
memory).
3)
The present counter value of 20 is stored in the present value buffer memory.
The value 200 that has been stored in the present value buffer memory will be
stored in the previous value buffer memory.
4)
The present counter value of 100 is stored in the present value buffer memory.
The value 20 that has been stored in the present value buffer memory will be
stored in the previous value buffer memory.
5)
The present counter value of 80 is stored in the present value buffer memory.
The value 100 that has been stored in the present value buffer memory will be
stored in the previous value buffer memory.
6)
The periodic pulse counter function is executed regardless of whether the count
enable command {Y04 (Y0C)} is ON or OFF.
7)
Value 1 is stored in the sampling/periodic counter flag storage buffer memory
{address B
H
(2B
H
)} while the periodic pulse counter function is being executed.
POINT
When reading a previous value {buffer memory address 10
H
to 11
H
(30
H
to 31
H
)}
and a present value {buffer memory address 12
H
to 13
H
(32
H
to 33
H
)} of the
periodic pulse count, read 4 contiguous words using the DFRO or BMOV
instruction.
[Program example]
H00 H10 D6 K2 DFRO
U0\G16 D6 K4 BMOV
Read command
Read command
Depending on the relation between the update timings of the previous and present
periodic pulse count values inside the module and the read timing in the sequence
program, the previous value may be the same as the present value.
If this has occurred, execute the reading again. (See Section 8.1.2, Section 8.2.2.)