Status Tags

You can define status tags in your Citect.ini file to allow the OPC driver to determine the current state of an OPC device. For example, a status tag could be configured to monitor an OPC item that indicates the current operational state of a connected device. If the condition of the status tag is true, the OPC driver can allow the device to come online; otherwise the device may be set to offline.

By default, no status tags are created for the OPC driver. They need to be defined in the project Citect.ini file using the OPC status tag parameters. These parameters determine which OPC items are monitored, the condition values, and how often polling occurs.

A status tag can be defined in the [OPCStatusTags] section of the Citect.INI file to determine the online status of OPC devices. You can also create status tag set for each individual I/O device using the following format:

[OPCStatusTags]
<IOServerName>.<IODeviceName>.<parameter>=<value>

For example:

[OPCStatusTags]
io1.iodev1.tag=ARB3183800_S_2.REQNUM
io1.iodev1.condition= <=10

Where "ARB3183800_S_2.REQNUM" refers to an OPC item configured in the device.

If you are not regularly reading from a particular device, it is recommended that you enable status units checks. To do this, you need to enable the parameter [IOServer]WatchDogPrimary.Standby units are enabled by default.

See Also

OPC Status Tag Parameters