Monitoring Network Status

The Network Status Display (NSD) fields are available for writing application programs and create displays that monitor and control iFIX networking. This section explains how to use the Network Status Display tag on the iClient to:

  • Monitor network status.
  • Monitor Enhanced Failover status and manually initiate failover to the standby SCADA.
  • Trigger an event on failover to the standby SCADA or LAN.

Monitoring Network Status

You can monitor the status of the network using the NSD diagnostic fields. This feature allows you to monitor sessions on your network, determine which nodes are active, and display the name of the local node. In the event that a SCADA Server becomes unavailable, you can also display an error code and text describing the current state of the connection with each SCADA Server.

iFIX provides the Network Status Display (NSD) tag that you can use when designing displays for monitoring and controlling Enhanced Failover and LAN Redundancy. This tag is not a database block. It is a special tag residing on each networked node that displays diagnostic, failover, and network information. Refer to the table of available Network Status Display fields in the Network Status Display Fields section.

To access the fields, use the server.node.NSD.field syntax. In the following example, PACKER1 is the local physical name. NSD is always the tag.

FIX32.PACKER1.NSD.A_PRIMARYSCADA_0

NOTE: TCP/IP networking must be enabled in the SCU to use NSD fields in iFIX.

Monitoring Enhanced Failover Status and Initiating Manual Failover to the Standby SCADA

Three NSD fields have been added for Enhanced Failover: SCADAREDUN, SCADASTATUS, and SWITCHSCADAROLE.

F_SCADAREDUN is a read-only field that returns an indication as to whether enhanced failover is enabled on the SCADA node. If Enhanced Failover is enabled, a 1 displays, and if it is disabled, a 0 displays.

F_SCADASTATUS and A_SCADASTATUS are read-only fields that return an indication as to whether the SCADA node is in an active state or the standby state. If the SCADA is in an active state, a 1 (or ACTIVE) displays, and if it is in the standby state, a 2 (or STANDBY) displays.

In addition to monitoring the SCADA status or having automatic SCADA failover, you can also manually force a SCADA failover to occur at any time. For example, you can manually switch to the standby SCADA node when the active SCADA node needs to be shut down for maintenance. When iFIX security is enabled, the Manual Failover application feature is checked prior to performing the manual SCADA failover. The Manual Failover application feature should be assigned to users or groups who are allowed to manually initiate SCADA failover.

F_SWITCHSCADAROLE and A_ SWITCHSCADAROLE are read/write fields that return an indication as to whether the SCADA node is in an active state or the standby state. If the SCADA is in an active state, a 1 (or ACTIVE) displays, and if it is in the standby state, a 2 (or STANDBY) displays. To perform a manual SCADA failover, a write of 1 (or ACTIVE) causes the SCADA to become the active SCADA. A write of 2 (or STANDBY) causes the SCADA to become the standby SCADA.    

Enabling/Disabling Drivers on SCADA Pairs

For the active SCADA node, you must enable its drivers so that it can poll for data. Similarly, for a standby SCADA you should disable its drivers in order to reduce the load on the PLCs.

For further information, refer to:

Triggering an Event on Failover

You may want to trigger an event when a SCADA failover occurs. For example, you may want to display a message informing the operator of the failover, and when the operator acknowledges the message, close a valve or sound an alarm. Use the Scheduler to create schedules to do this. Refer to the Creating and Editing Schedules and Entries section for more information.

To trigger an event on SCADA failover, write to the A_FAILOVER or F_FAILOVER Network Status Display field. This field is set to 1 on automatic or manual failover. You must reset it to 0 to receive notification of subsequent failovers.

To see if any connection has had a SCADA failover, read the F_SCADAANYFAILOVER field. It is set to non-zero if any F_FAILOVER field is set to non-zero.

To trigger an event on LAN failover, write to the F_LANFAILOVER or A_LANFAILOVER field. This field is set to 1 on LAN failover. You must reset it to 0.

To see if any connection has had a LAN failover, read to the F_LANANYFAILOVER field. It is set to non-zero if any F_LANFAILOVER field is set to non-zero.

For more information on the Network Status Display fields, refer to the Network Status Display Fields section.

See Also