Data Retention Time For System Switching - Mitsubishi Electric Melsec QJ71LP21 Reference Manual

7 APPLICATION FUNCTIONS

7.10.7 Data retention time for system switching

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This section describes the cyclic data retention time at another station when system
switching occurs in the redundant system.
Calculate the cyclic data retention time at another station based on:
• Monitoring time (Refer to Section 5.4);
• System switching monitoring time (Refer to Section 7.10.5);
• Control station shift time (Refer to Section 3.3.5);
• Redundant CPU system switching time (refer to the QnPRHCPU User's Manual
(Redundant System); and
• Redundant CPU scan time (refer to the QnPRHCPU User's Manual (Redundant
System).
The expression of the cyclic data retention time at another station depends on the
reason(s) for system switching.
Control system power supply module malfunction, power
supply off
Control system CPU malfunction, resetting
Control system CPU stop error
Execution of system switching instruction
System switching operation from GX Developer
System switching request from other network module
System switching request from network module (host station)
Reason
MELSEC-Q
Expression
Refer to (1) of this section.
Refer to (2) of this section.
Refer to (3) of this section.
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