Mitsubishi Electric MELSEC A Series User Manual page 41

(1) System design circuit example
AC system
Power supply
Transformer
Fuse
CPU
M9006
Ym
M9039
Yn
Start Program
switch
RA1
MC Stop
switch
Input unit
Output unit
Ym
Yn
Output unit
MC
MC2
MC1
The procedures used to switch on the power supply are indicated below.
AC system
[1] Switch the power supply ON.
[2] Set the CPU module to RUN.
[3] Switch the start switch ON.
[4] The output devices are driven in accordance
with the program when the magnetic
contactor (MC) comes ON.
DC power supply
established signal
input
Start/stop circuit
Can be started
by turning ON of
RA1, which is the
PC's RUN output.
MC
XM
Output for warning
(lamp or buzzer)
L
Turned ON in RUN
status by M9039
RA1
MC
Switches the power
supply to output devices
OFF when the system
stops:
At emergency stops
MC1
At stops on reaching a
limit
MC2
Interlock circuit
Constructs external
interlock circuits for
opposing operations
such as forward and
reverse rotation, and
parts that could cause
machine damage or
accidents.
AC/DC system
Power supply
Transformer
Fuse
CPU
M9006
Ym
M9039
Yn
XM
TM
TM
MC1 N0 M10
N0 M10
Start
Program
switch
RA1
MC
MC
Stop
switch
Input unit
RA2
Output unit
Ym
L
Yn
RA1
Output module
MC2
MC1
MC1
MC2
AC/DC system
[1] Switch the power supply ON.
[2] Set the CPU module to RUN.
[3] Switch RA2 ON when the DC power supply starts.
[4] Switch the timer (TM) ON when the DC power
supply reaches working voltage.
(The set value for TM must be the time it takes for
100% establishment of the DC power after RA2 is
switched ON. Make this set value 0.5 seconds.)
[5] Switch the start switch ON.
[6] The output devices are driven in accord-ance with
the program when the magnetic contactor (MC)
comes ON.
(If a voltage relay is used at RA2, no timer (TM) is
necessary in the program.)
28
DC power
supply
(-)(+)
Fuse
The setting for TM
is the time taken
to establish the
DC input signal.
Voltage relay
recommended
RA2
XM
Output for warning
(lamp or buzzer)
Turn ON in RUN
status by M9039
MC MC
Switches the power
supply to output
devices OFF when
the system stops:
At emergency stops
At stops on reaching
a limit