Mitsubishi Electronics Mitsubishi Digital Electronics Electronic Accessory Q02CPU ユーザーズマニュアル

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MELSEC-Q
 
9   LOADING AND INSTALLATION 
 
9 LOADING AND INSTALLATION 
In order to increase the reliability of the system and exploit the maximum performance 
of its functions, this section describes the methods and precautions for the mounting 
and installation of the system. 
 
9.1 General Safety Requirements 
!
 DANGER 
 Install a safety circuit external to the PLC that keeps the entire 
system safe even when there are problems with the external power 
supply or the PLC module. Otherwise, trouble could result from 
erroneous output or erroneous operation. 
(1) Outside the PLC, 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 PLC 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 stop calculation and hold or turn off all 
output according to the parameter setting. 
Note that the A1S series module will turn off the output in either 
of cases (a) and (b). 
All outputs of AnS Series Module will be switched off in the 
following cases: 
 
(a) The power supply module has over current protection 
equipment and over voltage protection equipment. 
(b) The PLC CPUs self-diagnosis functions, such as the watch 
dog timer error, detect problems. 
In addition, all output will be turned on when there are problems 
that the PLC CPU cannot detect, such as in the I/O controller. 
(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. 
 When overcurrent which exceeds the rating or caused by short-
circuited load flows in the output module for a long time, it may 
cause smoke or fire. To prevent this, configure an external safety 
circuit, such as fuse. 
 Build a circuit that turns on the external power supply when the PLC 
main module power is turned on. If the external power supply is 
turned on first, it could result in erroneous output or erroneous 
operation.  
 When there are communication problems with the data link, refer to 
the corresponding data link manual for the operating status of each 
station. Not doing so could result in erroneous output or erroneous 
operation.operating status of each station. Not doing so could result 
in erroneous output or erroneous operation. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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