Safety Remote Station Interlock Function - Mitsubishi Electric MELSEC QS Series User Manual

4
FUNCTIONS

4.2.14 Safety remote station interlock function

When an error causing I/O stop occurs in a safety remote station, or when a
communication error occurs between a safety master station and a safety remote station,
this function prevents automatic restart of input/output to/from the relevant safety remote
station(s), so that the machine will not suddenly restart causing a dangerous condition.
If the safety master station detects an error in communication with a safety remote station,
the corresponding station No. is identified as "Safety station interlock status".
[Safety monitoring timeout error]
A safety remote station monitors the time intervals between sending data to the safety
master station and receiving next data from the safety master station using the safety
refresh monitoring time and safety data monitoring time.
The safety remote station disconnects from the safety master station and waits for
reconnection if not being able to receive data from the safety master station exceeding the
safety refresh monitoring time or safety data monitoring time after sending data.
Safety master station
Safety remote station
Normal reception
Safety refresh
monitoring timer
Safety data
monitoring time 1)
Safety data
Measuring time
monitoring time 2)
4
- 30 4.2 Detailed Explanation of Functions
4.2.14 Safety remote station interlock function
Normal reception
Measuring time
Measuring time
Measuring time
Normal reception Data error
Measuring time
Safety refresh monitoring timer
Measuring time
Measuring time
Safety refresh monitoring timer
A safety remote station
disconnects from the
safety master
Safety monitoring
timeout error
occurred.
Safety monitoring
timeout error
occurred.