Introduction

Control Expert provides M580 Hot Standby System diagnostic information in the following GUI screens:

• the Hot Standby status viewer embedded in the Control Expert Task Bar.

• the Information tab of the CPU Animation window

Hot Standby Status Viewer

When Control Expert is connected to the Hot Standby system, it displays the Hot Standby status of each PAC, including:

• The status of CPUs A and B.

• The comparative state of logic running in the standby PAC.

• If a logic mismatch exists, the number of modifications made to the application running in the primary PAC.

The Hot Standby Status Viewer looks like this:

1 Hot Standby status

2 Number of changes

The status values for PACs A and B include:

• RUN_PRIMARY

• RUN_STANDBY

• STOP

• WAIT

Also presented is the logic state of the standby PAC, which can be either:

• EQUAL (green background): There is no logic mismatch.

• DIFFERENT (red background): Online changes have been made to the primary PAC application that have not been transferred to the standby PAC.

An additional status information is displayed when at least one task (MAST, FAST, or SAFE) is not synchronized between the Primary and the Standby PLCs: TASK NOSYNC (red background):

In this case, it is recommended to analyze "MAST_SYNCHRONIZED", "FAST_SYNCHRONIZED" and "SAFE_SYNCHRONIZED" data provided in T_M_ECPU_HSBY DDT in order to detect the task which is not synchronized.

Hot Standby Information Tab

Use the CPU Configuration window Animation > Information tab to view the status of the Hot Standby system:

The Information tab contains one word of status data, as follows: