Applies To:
  • CitectSCADA 6.xx
  • CitectHMI 6.xx

In a redundant, pure TCP/IP network (where NetBIOS is disabled on both Servers), the following DNS parameters have been defined on the Primary and Standby Servers:


In runtime, when an alarm have been triggered on and off, acknowledging the alarm on the Primary server will work but the alarm will not get acknowledged on the Standby server.
Similarly when acknowledging alarms on a standby server they are not seen as acknowledged on the Primary server.

The alarm will display as acknowledged on both Servers when you use the extended DNS parameter to specify your servers as shown below.
Adding the following DNS parameters to both INI files worked around this issue.


The names above can be verified against the INI files on the Primary and Standby servers:

From Primary INI:

Name= IOServerP

From Secondary INI:

Name= IOServerS

Citect has confirmed this to be a problem in CitectSCADA versions 6.00.  It is fixed in version 6.10.


Alarms, Acknowledge, Redundancy, TCPIP