To view NSD field names in the iFIX Expression Builder, you must have TCP/IP networking enabled in the SCU (in the Network Configuration dialog box). The NSD tag is not supported in iFIX Demo mode. Refer to the Network Status Display Tag section for more information.
NSD fields can be used in datalinks, for instance, to provide information on the current status of the SCADA network. In addition to the fields that already existed in previous releases, you can use the following new NSD fields in datalinks to monitor and switch the SCADA status:
- Fix32.physicalnodename.NSD.F_SCADAREDUN to display if Enhanced Failover is enabled on a SCADA node.
- Fix32.physicalnodename.NSD.F_SCADASTATUS (or A_SCADASTATUS) to display the current failover status of SCADA node.
- Fix32.physicalnodename.NSD.F_SWITCHSCADAROLE (or A_ SWITCHSCADAROLE) to force the failover status of the active SCADA node to standby or of the standby SCADA node to active.
Other examples are provided in the following sections.
SCADA Failover
You can identify when a SCADA Server failover has occurred using a Network Status Display field (for example, (A_FAILOVER_0 through A_FAILOVER_200, F_FAILOVER_0 through F_FAILOVER_200), or through the alarm messages.
iFIX sends an alarm message whenever SCADA Server failover occurs.
For example, if you are communicating from an iClient named LN1_VIEW to a primary SCADA node named FOXBORO, and the active SCADA fails over to the secondary SCADA node named ALBANY, the message on the iClient is:
06/07/2013 16:35:21.5 [FOXBORO] SAC is in Standby mode
06/07/2013 16:35:22.5 Connection Failover: failover attempted
06/07/2013 16:35:22.5 Connection Failover: connection to FOXBORO has been switched to ALBANY
06/07/2013 16:35:21.5 [ALBANY] SAC is in Active mode
LAN Failover
You can use a Network Status Display field (A_LANFAILOVER_0 through A_LANFAILOVER_200, F_LANFAILOVER_0 through F_LANFAILOVER_200) or the messages to identify when a LAN failover has occurred.
iFIX sends a message whenever LAN failover occurs.
For example, if you are communicating from an iClient named LN1_VIEW over TCP/IP address 1.1.1.2 to a SCADA node named FOXBORO, and the session is lost and re-established over TCP/IP address 198.212.170.4, the message on the iClient is:
19:24:00.0 [LN1_VIEW] Connection to [FOXBORO]
switched to 1.1.1.2 - 1.1.1.5 to 198.212.170.4 - 198.421.103.6
