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MITSUBISHI ELECTRIC 700 Series User Manual

Page 93

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88

Special Relays, Special Registers

Table3.4 Special Relay Application List

Item

Special

Relay

Application/Description

Initial
processing
flag
(1 scan ON)

M9038

(1)This relay turns on for one scan when the built-in PLC function

switches from STOP to RUN.

(2)Using M9038, you can create a sequence program to be

executed only once without using the PLS instruction at
switching from STOP to RUN.

Normal OFF
flag

M9037

This relay remains off while power is on.
Can be used to temporarily disable execution for debugging, etc.

Normally ON
flag

M9036

This relay is on while power is on.
Can be used to create a program to be executed only once after
power-on.

RUN flag

M9039

This relay turns on at the second scan of the sequence program
when SQ-SD are shorted.

ON

M9038

OFF

Switching from STOP to RUN

0

Sequence
program

1 scan

END/0 END/0 END/0 END/0

M9038

Initial processing program

M9039

OFF

RUN

0

Sequence
program

END/0

ON