Applies To:
  • CitectSCADA 3.xx, 4.xx, 5.xx

The Citect SFDL and SINECFDL drivers, used for communications to Siemens S5 series PLCs, do not support redundancy. 

CIT has confirmed this to be a problem from Citect for Windows version 4.20 onwards. We are researching this problem and will post new information here as it becomes available.

The SFDL and SINECFDL drivers require software in the PLC to operate. This software currently supports only one connection, and so redundant Citect's cannot connect to a single PLC. Modification of the PLC program, and subsequently the Citect drivers, is required to support more than one connection.