Calculation Example For Response Time - Mitsubishi Electric MELSEC iQ-R Series Safety Manual

Calculation example for response time

The following shows calculation examples.
• Safety cycle time: 3ms (SCcpu)
• Safety remote I/O module input response time: 1.4ms (SRin)
• Safety remote I/O module output response time: 0.4ms (SRout)
• Safety remote station refresh response processing time: 2ms
Calculation example of the CC-Link IE Field Network transmission time
Calculation example of CC-Link IE Field Network transmission time
■Calculation example of CC-Link IE Field Network link scan time (LS)
Link scan time (LS) is used for calculation of the CC-Link IE Field Network transmission time. (Condition: No communication
error station exists)
For Ka to Ke, use values when the station is set to normal mode.
RX/RY total number of set points becomes 256, while RWr and RWw total number of set points becomes 320.
Set transient transmission are switching hub to not used, and set submaster station to not set.
LS = [{(Total number of set points for RX and RY)  4 + (Total number of set points for RWr and RWw)  4}  0.08 + (Number
of slave stations actually connected  Ka) + Kb + Kc + Kd] 1000 + (Number of interrupt conditions in the interrupt setting) 
0.02 + (Total Ke of each unit)  1000 + St [ms]
= {(256  4 + 320  4)  0.08 + (2  25.8) + 655 + 0 + 0}  1000 + 0  0.02 + 42.8  1000 + 0
 0.86 [ms]
■Calculation example of CC-Link IE Field Network transmission interval monitoring time
Transmission interval monitoring time is used for calculation of the CC-Link IE Field Network transmission time. According to
Page 237 CC-Link IE Field Network transmission interval monitoring time, all calculation formulas in (1) to (4) below must be
satisfied.
• CC-Link IE Field Network master/local module (Set the time in increments of 0.1ms.)
(1) Transmission interval monitoring time  SCown  3 = 3  3 = 9  9 [ms]
(2) Transmission interval monitoring time  SRref  2 + LS  2 = 2  2 = 0.86  2 = 5.72  5.8 [ms]
• Safety remote I/O module (Set the time in increments of 1ms.)
(3) Transmission interval monitoring time  SRref  2 = 2  2 = 4 [ms]
(4) Transmission interval monitoring time  SCmst  2 + LS  2 = 3  2 + 0.86  2 = 7.72  8 [ms]
SCown: Safety cycle time of the master station
SCoth: Safety cycle time of the communication destination
SCmst: Safety cycle time of the master station
SRref: Safety remote station refresh response processing time
LS: Link scan time
Therefore, set the transmission interval monitoring time of the CC-Link IE Field Network master/local module to 9ms. Set the
transmission interval monitoring time of the safety remote I/O module to 8ms.
■Calculation example of safety refresh monitoring time on CC-Link IE Field Network
Safety refresh monitoring time is used for calculation of the CC-Link IE Field Network transmission time. According to Page
238 Safety refresh monitoring time on CC-Link IE Field Network, all calculation formulas in (1) to (4) below must be satisfied.
(1) Safety refresh monitoring time  TMact + (TMpas  2) + (LS  2) - a = 9 + (8  2) + (0.86  2) - (9 - 6) = 11.72  11.8 [ms]
(2) Safety refresh monitoring time  (TMact  2) + TMpas + (LS  2) - c = (9  2) + 8 + (0.86  2)- (8 - 4) = 10.22  10.3 [ms]
(3) Safety refresh monitoring time > TMact = 9 [ms]
(4) Safety refresh monitoring time > TMpas = 8 [ms]
TMact: Transmission interval monitoring time for a station set to the active side
TMpas: Transmission interval monitoring time for a station set to the passive side
LS: Link scan time for the CC-Link IE Field Network
a: If a station is set to the active side is RJ71GF11-T2, then a = TMact - b. For other cases, a = 0.
b: Value rounds up the calculation results of the TMact  2 to a multiple of the safety cycle time of the master station.
c: If a station is set to the passive side is either RJ71GF11-T2 or NZ2GFSS2-32D, then c = TMpas - d. For other cases, c = 0.
d: Value rounds up the calculation results of the TMpas  2 to a multiple of the safety cycle time of the local station (if NZ2GFSS2-32D, safety refresh response
processing time)
Set the safety refresh monitoring time to 11.8ms to satisfy all in (1) to (4) above.
APPX
240
Appendix 1 Calculating Safety Response Time for System Configured with a Safety CPU