Specifications Of The Redundant System; Specifications Of The System Using A Sil2 Process Cpu - Mitsubishi Electric MELSEC iQ-R Series Manual

Specifications of the redundant system

This section describes the specifications of online module change for the redundant system.
• Both in backup mode and in separate mode, online module change is permitted.
• Both in the control system and in the standby system, online module change is permitted.
• The output (Y) to the module being changed online will be held. However, in the redundant system, an output (Y) may turn
off due to system switching or operation mode change during online module change. In this case, the output (Y) to the
module being changed online also turns off.
• The online module change cannot be performed while the memory copy is being executed. Perform the online module
change again after the memory copy is completed.
• In direct change, a continuation error may occur even if "RAS Setting" is set to choose a stop error, and this causes an error
that the system is not switched. When performing a direct change as a method of the online module change, check that it
does not affect the system. If it affects the system, perform the online module change using special relays and special
registers instead of the direct change.

Specifications of the system using a SIL2 Process CPU

This section describes the specifications of online module change for the system using a SIL2 Process CPU.
• Both in the control system and in the standby system, online module change is permitted.
• The output (Y) to the module being changed online will be held. However, in the system using a SIL2 Process CPU, an
output (Y) may turn off due to system switching during online module change. In this case, the output (Y) to the module
being changed online also turns off.
• The online module change cannot be performed while the memory copy is being executed. Perform the online module
change again after the memory copy is completed.
• In direct change, a continuation error may occur even if "RAS Setting" is set to choose a stop error, and this causes an error
that the system is not switched. When performing a direct change as a method of the online module change, check that it
does not affect the system. If it affects the system, perform the online module change using special relays and special
registers instead of the direct change.
• The online module change cannot be performed while online operation is being performed from an engineering tool. Or
online module operation cannot be performed from an engineering tool during online module change.
3 REPLACEMENT PROCEDURE
3.1 Specifications
3
21