Mitsubishi Q172CPU User Manual page 130

3 DESIGN
The power-ON procedure is as follows:
For AC/DC
1) Switch power ON.
2) Set CPU to RUN.
3) When DC power is established, RA2 goes ON.
4) Timer (TM) times out after the DC power reaches 100[%]. (The TM set value should be the period of time
from when RA2 goes ON to the establishment of 100[%] DC voltage. Set this value to approximately 0.5
seconds.)
5) Turn ON the start switch.
6) When the electromagnetic contactor (MC) comes on, the output equipment is powered and may be driven
by the program. (If a voltage relay is used at RA2, no timer (TM) is required in the program.)
(b) System design circuit example(when using ERR contact of
power supply module)
DC power supply
established signal input
START/STOP circuit
Starting possible
when the PLC RUN
output RA1 is ON
Power supply module
Interlock circuits as
necessary. Provide
external interlock
circuits for conflicting
operations, such as
forward rotation and
reverse rotation,
and for parts that could
damage the machine or
cause accident if no
interlock were used.
Power supply
Transformer
Fuse
CPU
SM52
Ym
SM403
Yn
XM
TM
N0
TM
MC1 N0 M10
M10
Program
Start Stop
switch switch
RA1
RA3
MC
MC
RA2
output module
Ym
Yn
ERR
output module
MC2
MC1
3 - 11
Using AC and DC
Transformer
Fuse
DC power
supply
(-) (+)
Fuse
Set TM to time
to establish
DC input signal
RA2
A voltage relay
is recommended
Input module
XM
Alarm output
L
(lamp or buzzer)
RA1
RA3 switched
OFF by ERR
RA3
MC MC
Turns output equipment
power off when ERR
switch OFF
on emergency stop,
MC1
on stop at upper/lower
limit switch
MC2