Transmission Delay Time Of Safety Communications - Mitsubishi Electric RD77GF8 User Manual

Transmission delay time of safety communications

The following are the formulas to calculate transmission delay time of safety communications.
Transmission delay time
■Master station (safety station) or local station (safety station)  Local station (safety station)
The following table lists the time between a safety device of the Safety CPU on the sending station turning on or off and that
on the receiving station turning on or off.
Calculation value
Normal value
Maximum value
SCsnd: Safety cycle time of the sending station (MELSEC iQ-R CPU Module User's Manual (Application))
LS: Link scan time (Page 169 Link scan time)
SCrcv: Safety cycle time of the receiving station (MELSEC iQ-R CPU Module User's Manual (Application))
TMsnd: Transmission interval monitoring time of the sending station (Page 175 Transmission interval monitoring time)
■Master station (safety station)  Remote device station (safety station) (input)
The following table lists the time between a signal input to the remote device station (safety station) and a safety device of the
Safety CPU on the master station (safety station) turning on or off.
Calculation value
Normal value
Maximum value
SCmst: Safety cycle time of the master station (safety station) (MELSEC iQ-R CPU Module User's Manual (Application))
LS: Link scan time (Page 169 Link scan time)
SRref: Safety remote station refresh response processing time (Manual for the remote device station used)
TMrmt: Transmission interval monitoring time of the remote device station (safety station) (Manual for the remote device
station used)
SRin: Safety remote station input response time (Manual for the remote device station used)
■Master station (safety station)  Remote device station (safety station) (output)
The following table lists the time between a safety device of the Safety CPU on the master station (safety station) turning on or
off and the output of the remote device station (safety station) turning on or off.
Calculation value
Normal value
Maximum value
SCmst: Safety cycle time of the master station (safety station) (MELSEC iQ-R CPU Module User's Manual (Application))
LS: Link scan time (Page 169 Link scan time)
SRref: Safety remote station refresh response processing time (Manual for the remote device station used)
TMmst: Transmission interval monitoring time of the master station (safety station) (Page 175 Transmission interval
monitoring time)
SRout: Safety remote station output response time (Manual for the remote device station used)
Safety response time
The safety response time is the maximum value of the time between a safety input of the remote device station (safety station)
turning off and a safety output of the remote device station (safety station) turning off (including an error detection time).
For calculation method of the safety response time, refer to the following.
Mitsubishi Safety Programmable Controller MELSEC iQ-R Series Machinery Directive (2006/42/EC) Compliance
APPX
174
Appendix 6 Processing Time
Formula
SCsnd + LS + SCrcv + TMsnd
SCsnd + (LS  2) + (SCrcv  2) + TMsnd
Formula
SCmst + LS + SRref + TMrmt + SRin
(SCmst  2) + (LS  2) + SRref + TMrmt + SRin
Formula
SCmst + LS + SRref + TMmst + SRout
SCmst + (LS  2) + (SRref  2) + TMmst + SRout