Mitsubishi Electric Melsec-Q172DCPU User Manual page 142

3 DESIGN
Input switched when
power supply established
RUN/STOP circuit
interlocked with RA1
(run monitor relay)
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.
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 magnetic 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 terminal of
power supply module)
Power supply
Transformer
Fuse
NO
START SW
RA1
MC
STOP SW
RA2
Output module
Ym
Yn
ERR
Output module
FOR AC/DC
Transformer
Fuse
CPU module
SM52
DC power
Ym
(-) (+)
SM403
Yn
XM
TM
TM
MC1 NO M10
M10
Program
RA3
MC
RA2
XM
L
RA1
RA3
MC
MC2
MC1
MC1
MC2
3 - 7
Fuse
Set time for DC power
supply to be established.
Voltage relay is
recommended.
Low battery alarm
(Lamp or buzzer)
OFF at ERR contact OFF
(stop error occurrence)
MC
Output by ERR contact OFF
Power OFF of equipment
In the case of an
emergency stop or a
stop caused by a limit
switch.