Applies To:
  • CitectSCADA 5.50 Service Pack B, 5.50 Service Pack C, 6.00
  • CitectHMI 5.50 Service Pack B, 5.50 Service Pack C, 6.00

The order in which I/O devices are configured has been reported to cause different problems. How should I configure my I/O devices to avoid such issues?

Citect has confirmed this to be a problem in CitectHMI/SCADA version 5.50 SP B to v6.0. To avoid the issues, Citect Support suggests that you setup your units.dbf in the following way:

IOServer1 PLC1 Primary
IOServer1 PLC2 Primary
IOServer2 PLC3 Primary
IOServer2 PLC4 Primary
IOServer2 PLC1_S Standby
IOServer2 PLC2_S Standby
IOServer1 PLC3_S Standby
IOServer1 PLC4_S Standby

Please be aware that not ordering your devices can result in the following:

* Devices will come online, but no data is visible on the page
* Communication is very slow

We are researching this problem and will post new information here as it becomes available.