Single CS31 Bus on CPU COM Port

HA_CS31_CONTROL function block handles HA-CS31 operation such as change over from primary to secondary CPU in case of fault with related diagnostics and also data transfer between HA-CS31 CPUs. This is a mandatory function block for High Availability to run. For further information on this function block, please refer to HA_CS31_CONTROL - HA Control FB.

HA_CS31_DIAG function block will be used to get diagnostic information only from CPU COM1 CS31 line. For further information on this function block, please refer to HA_CS31_DIAG - Reading HA Diagnosis.

HA_CS31_DATA_SYNC function block is used for synchronizing non High Availability function blocks or any other data. For further information on this function block, please refer to HA_CS31_DATA_SYNC - HA Data Synchronization FB.

High Availability Utility function blocks outputs are internally synchronized and can be used directly without using HA_CS31_SYNC function block. For further information on these function blocks, please refer to Utility Function Blocks.

Visualization

High Availability overview visualization can be used for monitoring purpose but it will show data only for the CPU on which we are logged into.

The following picture describes the visualization screen of a running HA-CS31 system with the CS31 lines only on the PLC COM port:

Visualization of AC500 High Availability System. Option 1.

DigiVis and OPC server can be used to write data as it will allow the user to write data to both PLCs at the same time. Data is read out from the primary PLC only. We recommend you, not to use HMI for writing data as it is not written to both PLCs.

Note

If during the startup of the HA-CS31 system none CI590-CS31-HA module is powered on, or if all CI590-CS31-HA modules have a wrong module address, the system does not become stable.

If any CI590-CS31-HA module address has been changed after startup of the HA-CS31 system the system will continue to run as it is. In order to activate the new address the complete system must be restarted.

If any CI590-CS31-HA module is powered off and on, there is no need to power restart the complete system from library version V2.4.2 onwards. Sync LED of failed CI590 line will blink and has to be acknowledged by the user.

For further information, please refer to both, the online help for HA-CS31 function blocks ( AC500 High Availability CS31 Library) and the Example_AC500_HA_CS31_V242_3ADR023070M0201.pdf.