Mitsubishi Q01CPU User Manual page 4

[Design Precautions]
Install a safety circuit external to the programmable controller that keeps the entire system safe even
when there are problems with the external power supply or the programmable controller. Otherwise,
trouble could result from erroneous output or erroneous operation.
(1) Outside the programmable controller, construct mechanical damage preventing interlock circuits
such as emergency stop, protective circuits, positioning upper and lower limits switches and
interlocking forward/reverse operations.
(2) When the programmable controller detects the following problems,
it will stop calculation and turn off all output in the case of (a).
In the case of (b), it will hold or turn off all output according to the parameter setting.
Note that the AnS/A series module will turn off the output in either of cases (a) and (b).
(a) The power supply module has
over current protection
equipment and over voltage
protection equipment.
(b) The CPU module self-diagnosis
functions, such as the watchdog
timer error, detect problems.
In addition, all output will be turned on when there are problems that the programmable
controller CPU cannot detect, such as in the I/O controller. Build a fail safe circuit exterior to the
programmable controller that will make sure the equipment operates safely at such times.
Refer to " LOADING AND INSTALLATION" in this manual for example fail safe circuits.
(3) Output could be left on or off when there is trouble in the outputs module relay or transistor. So
build an external monitoring circuit that will monitor any single outputs that could cause serious
trouble.
A
- 2
DANGER
Q series module
Output OFF
Hold or turn off all
output according to
the parameter setting.
AnS/A series module
Output OFF
Output OFF