Mitsubishi Electric MELSEC-QS Series Safety Application Manual page 168

APPENDICES
Transmission time of CC-Link IE Field Network = (Safety refresh monitoring time of CC-Link IE Field Network
APPX
Appendix 2 Calculating Safety Response Time When CC-Link Safety and CC-Link IE Field Network are
- 12
Used
(c) Calculating transmission time of CC-Link IE Field Network
The following is the formula to calculate transmission time [ms] of CC-Link IE
Field Network.
1) Safety refresh monitoring time of CC-Link IE Field Network
This time is required to calculate the transmission time of CC-Link IE Field
Network. This is the time monitored by the receiving station for each safety
connection to detect the following safety communication errors.
• Safety communication stop due to an error on the sending station
• Safety communication stop due to an error on the transmission path, such
as cable disconnection or hub failure
Set the time to one of the safety stations (active side) that performs safety
communication.
*1 The active side and the passive side use the same safety refresh monitoring time.
Safety refresh monitoring time
LS : Link scan time of CC-Link IE Field Network (Refer to Appendix 2 (1) (c) 3).)
: • Number of safety connections on the active side
connections on the passive side:
Number of safety connections on the active side
(Round up the calculated value to the nearest integer.)
• Number of safety connections on the active side
connections on the passive side:
Number of safety connections on the passive side
(Round up the calculated value to the nearest integer.)
If time between a safety data reception and the next safety data reception on
the receiving station exceeds the safety refresh monitoring time, the receiving
station detects an safety monitoring timeout error and stops safety
communication. The safety data to be received from the sending station is
cleared at the time.
POINT
When the safety CPU module detects a safety monitoring timeout error, check if
the safety refresh monitoring time satisfies the formula above.
- (Transmission interval monitoring time of CC IE master
- (Transmission interval monitoring time of CC IE local
+ (WDT(2) 3) [ms]
*1
The time value must satisfy the following formula.
Transmission interval monitoring time (active side)
+ Transmission interval monitoring time (passive side)
+ LS ( + 1) [ms]
4)
3)
4)
Number of safety
8
Number of safety
8