Precautions For Programming - Mitsubishi Electric MELSEC-QS Series Safety Application Manual

4
PRECAUTIONS FOR USE OF SAFETY
PROGRAMMABLE CONTROLLER
4.2

Precautions for Programming

(1) Basic programming
Configure a program for realizing safety functions with attention to the following
points.
Operation function
(Non-safety related parts)
Operation command
Start switch
Reset switch
For program examples, refer to CHAPTER 5 and CHAPTER 6.
• Program so that a machine is started only when safe state can be confirmed at
the time the start switch is pressed.
• Program so that a machine is stopped if the safe state is not confirmed.
• Program so that a machine is started at the fall (on
switch.
The programming can prevent a machine from accidentally starting at the switch
failure (such as contact welding, spring damage).
• To inhibit restart without manual operation after safety functions were performed
and outputs were turned off, create an interlock program which uses a reset
button for restart.
Start
request
Safety
programmable
controller
Safety
input data
Safety status
No entering detection to hazardous area
No emergency stop request
The safety programmable controller and
components are not faulty status.
Figure 4.6 Configuration example of safety-related system
off) of the signal of the start
(Start command signal)
Safety
Machine operation
output data
(startup)
Interlock
4.2 Precautions for Programming
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