Mitsubishi Electronics FX3G User Manual

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3UC
 Series
Programming Manual - Basic & Applied Instruction Edition
37 Operation of Special Devices (M8000 -, D8000 -)
37.2 Supplement of Special Devices (M8000 - and D8000 -)
37.2
Supplement of Special Devices (M8000 - and D8000 -)
This section explains how to use the provided special devices to activate built-in PLC functions for additional program
control.
37.2.1 RUN monitor and initial pulse [M8000 to M8003]
1. RUN monitor (M8000 and M8001)
The RUN monitor (M8000 and M8001) may be used to continually drive an output during PLC "normal operation".
1) Example program
M8001 is always OFF while the PLC is in the RUN mode.
2) Flag operation timing
2. Initial pulse (M8002 and M8003)
The initial pulse M8002 & M8003 is turned to ON or OFF respectively during the 1st scan of the PLC program.
It can be utilized as an initial setting signal in a program for initializing the program, for writing a specified value, or for
another purpose.
1) Example program
M8003 turns OFF momentarily (for only 1 scan time) when the PLC enters the RUN mode.
2) Flag operation timing
M8000
RUN monitor (NO contact)
Always ON while the PLC
is in RUN mode.
"Normal operation"
Y000
Output to be always driven
RUN input
RUN
STOP
RUN
M8000
RUN monitor (NO contact)
ON
ON
M8001
RUN monitor (NC contact)
ON
M8002
Initial pulse (NO contact) ON
ON
1 scan time
M8003
Initial pulse (NC contact)
ON
ON
M8002
Initial pulse (NO contact)
FNC 40
ZRST
D200
D299
The latched (battery backed) type data registers D200
to D299 are cleared.
RUN input
RUN
STOP
RUN
M8000
RUN monitor (NO contact)
ON
ON
M8001
RUN monitor (NC contact)
ON
M8002
Initial pulse (NO contact) ON
ON
1 scan time
M8003
Initial pulse (NC contact)
ON
ON