Mitsubishi Electric MELSEC iQ-RJ71GF11-T2 - Page 378

376
APPX
Appendix 7 Processing Time
Line redundant
The following are the formulas to calculate safety data holding time when system switching occurs in the line redundant
configuration.
*1
*1 The variables in the equation have the following meaning.
*2 For delay time until detection of the system switching cause, refer to the following.
 MELSEC iQ-R CPU Module User's Manual (Application)
*3 Depending on the failure status of the power supply module, the calculation formula of the safety data holding time (SH) may be as
follows.
100 + (2  LS) + Tsw + Tso + TMmst
*4 When the redundant function module is disconnected from the base unit or depending on the failure status of the base unit, the safety
data holding time (SH) may be calculated by the following formula.
2.5 + (4  LS) + Tsw + Tso + TMmst
Pattern No. System switching cause Safety data holding time (S
H
) [ms] Timing chart
1 • Failure of the control system power supply module
*3
• Power-off of the control system
• Failure of the control system SIL2 process
• Failure of the control system base unit
*4
• Failure of the control system redundant function
module
*4
Delay time until detection of the system switching
cause
*2
+ Tsw + Tso + TMmst
Page 377 Pattern 1
2 • Stop error of the control system SIL2 process
• Execution of the system switching instruction
• System switching request from the engineering tool
• System switching request from another network
module
Delay time until detection of the system switching
cause
*2
+ Tsw + Tso + TMmst
Page 377 Pattern 2
3 System switching request from the RJ71GF11-T2 (own
station)
5 + Tc + (3  LS) + Tsw + Tso + TMmst + SS Page 378 Pattern 3
Variable Meaning
Tsw SIL2 Process CPU system switching time [ms] ( MELSEC iQ-R CPU Module User's Manual (Application))
Tso Delay time until initial safety output after system switching ( MELSEC iQ-R CPU Module User's Manual (Application))
TMmst Transmission interval monitoring time of the master station (safety station) [ms] ( Page 348 Transmission interval monitoring time)
SS SIL2 Process CPU sequence scan time [ms] ( MELSEC iQ-R CPU Module User's Manual (Application))
Tc System switching monitoring time setting value [ms] ( Page 139 Supplementary Cyclic Settings)
LS Link scan time [ms] ( Page 341 Link scan time)