Applies To:
  • CitectSCADA 4.10

A Gem 80 PLC is multidropped to 2 Citects (Primary and Standby) by a current loop connection and via RS232 PC8i digiboards.

A primary I/O Server is running and communicating with a Gem 80 PLC. When the Standby I/O Server is started it crashes immediately at startup.

The reverse is also true. ie if the Standby is running and communicating to the Gem 80 PLC, and the Primary I/O Server is started, it also crashes leaving the Standby running.


CIT has confirmed this to be a problem in Citect for Windows version 4.10. This problem has been fixed in version 4.20 or you may pick up a the latest COMX.DLL from the FPT site.