Cyclic Data Holding Time When System Switching Occurs - Mitsubishi Electric MELSEC iQ-R Series User Manual

Cyclic data holding time when system switching occurs

This section describes cyclic data holding time when system switching occurs.
Calculation formula
The following are the formulas to calculate cyclic data holding time when system switching occurs.
Pattern System switching cause
number
1 • Power-off of the control
system
• Failure of the control system
CPU module
• Failure of the control system
base unit
2
3
4 • Stop error of the control
system CPU module
• Execution of the system
switching instruction
• System switching operation
from the engineering tool
• System switching request
from another network module
5 System switching request from
the RJ71LP21-25 (own station)
*1 For delay time until detection of the system switching cause, refer to the following.
 MELSEC iQ-R CPU Module User's Manual (Application)
The meaning of the variables in the equation are as follows.
Variable Meaning
T Cyclic data holding time [ms]
H
Tsw CPU module system switching time [ms] ( MELSEC iQ-R CPU Module User's Manual (Application))
Tjo Delay time until initial output after system switching [ms] ( MELSEC iQ-R CPU Module User's Manual (Application))
Tc System switching monitoring time [ms] (Setting value of "System Switching Monitoring Time" of the network parameter) ( Page 65
Supplementary Cyclic Settings)
Td Data link monitoring time [ms] (Setting value of "Data Link Monitoring Time" of the network parameter) ( Page 65 Supplementary Cyclic
Settings)
Csw Control station switching time
Csw [ms] = (a  12) + (b  11) + (c  3) + 450
a: Number of the normally operating stations after disconnection of the control station
b: Number of the faulty stations after disconnection of the control station
c: Constant link scan setting value (Page 65 Supplementary Cyclic Settings)
SS CPU module sequence scan time [ms] ( MELSEC iQ-R CPU Module User's Manual (Application))
Nc Line control time for one station
The time for reconfiguring the data link if the RJ71LP21-25 is disconnected or reset by cable disconnection or powering off and on the
system.
Cyclic transmission status and baton pass status will be error on all stations for up to 100ms. (Normal status: 50ms or less)
If the constant link scan time setting value is large, it takes a lot of time before the start of line control, and there are cases where the time
required for completion of reconfiguration of the data link exceeds 100ms.

Module internal processing time
[ms] = 150ms (Constant)
Condition Cyclic data holding time (T
• The control Delay time until detection of the system switching
*1
station is in a cause
+ Tsw + Csw + SS
redundant
system.
• Tjo < Csw
• The control Delay time until detection of the system switching
*1
station is in a cause + Tsw + Tjo + SS
redundant
system.
• Tjo > Csw
A normal station is
in a redundant
system.

Delay time until detection of the system switching
*1
cause + Tsw + Tjo + SS
Delay time until detection of the  + Td + Tc system

switching cause
) [ms]
H
*1
+ Tsw + Tjo + SS
Appendix 6 Processing Time
Timing chart
Page 182 Pattern 1
Page 183 Pattern 2
Page 184 Pattern 3
Page 185 Pattern 4
Page 186 Pattern 5
A
APPX
181