Associated with: Scanners; outstations that support this feature
Security permission required to access this pick action: Retrieve Data
Geo SCADA Expert typically scans devices for data on a scheduled basis. If required, you can use the Refresh pick action to scan a device on demand. Select the Refresh pick action to request a current data update of the points on a particular outstation or scanner.
Do not use the Refresh pick action excessively. Excessive use of the Refresh pick action could adversely impact the performance of your system.
Depending on the protocol, a Refresh either:
- Triggers an immediate scan of the outstation or scanner—The Refresh action completes once Geo SCADA Expert has scanned each of the points on the outstation or scanner and has processed that data. This is the most common type of Refresh action. It typically applies to scanners on simple drivers, and to outstations on many advanced drivers.
The Source Refresh system color indicates when a Refresh is in progress.
If required, use the Cancel Refresh pick action to cease such a refresh.
- Marks each point on the scanner or outstation as having data to report—The Refresh action completes immediately. In the next scan of the outstation or scanner, Geo SCADA Expert retrieves current data from each of the points on that device, regardless of whether that data has changed since the last retrieval. This type of Refresh action applies to outstations on some advanced drivers.
A Refresh differs from a normal scan (poll) in that it forces all points to be updated on the scanner or outstation on which the Refresh is triggered, regardless of whether the points' values have changed. (Whereas an scan (poll) typically only updates those points for which the values are deemed to have changed sufficiently (taking into account any configured Significant Change deadbands, Persistence, and so on).)
The Refresh pick action is only available on an outstation that communicates via PSTN while that outstation is on line (for instance, during an Open Line call). When a call is not in progress, use the One Shot pick action to contact the outstation and ‘refresh’ that outstation’s data.
Do not confuse this Refresh pick action with the Refresh menu options or buttons that are available for various Geo SCADA Expert displays, such as:
- Status Displays—see Status Displays in the Geo SCADA Expert Guide to ViewX and Virtual ViewX Clients.
- Lists—see Refresh the Data on a List other than an Alarms List in the Geo SCADA Expert Guide to Lists.
- Geo SCADA Expert Server Status Tool—see Server Status Menu in the Geo SCADA Expert Guide to the Server Status Tool.
- Archive Volumes Manager—see Archiving in the Geo SCADA Expert Guide to Server Administration.