Configure scan types

The points are collected based on the scan type and scan rate. You must ensure that the scan types and scan rates are correctly configured for the data collection service.
When you add points using the
Add Points Wizard
 page (see Add points using the Add Points Wizard page), make sure to set the correct scan type in the rule file.
When you create individual points manually (see Create points), make sure to set the correct scan type in the point attributes.
The following scan types are available:
Scan type
Description
Polled
Polled tags are scanned and the data event (with a value and a timestamp) is sent to the local
FactoryTalk Historian ME
 server at the specified scan time interval.
Usually, polled tags are intended for scan rates greater than 0.5 seconds.
Advised
Advised tags are scanned for new values at timed intervals that are defined by the scan class. However, a new event happens (becomes available) only if the value has changed from the previous event.
Usually, advised tags are intended for scan rates greater than 0.5 seconds. A point will not be put on the scan if it is configured at a rate faster than 0.5 seconds.
If you need data collection rates faster than 0.5 seconds, use high-speed tags.
Trigger Input
Triggered input tags are used to collect a data point after a particular triggering event has occurred.
Use this scan type for trigger input tags.
Output
Triggered output tags are used to output (write-back) a data point to a controller after a particular triggering event has occurred.
Output scan types are not supported for tags created from shortcuts pointing to remote controllers.
High-speed
High-speed tags are scanned and the data event (with a value and a timestamp) is logged at the specified scan time interval.
Usually, high-speed tags are intended for fast data collection speeds with scan rates of 10 ms. A point will not be put on the scan if it is configured at a rate slower than 0.5 seconds.
The module will not allow high-speed tags to be created with a scan rate slower than 500 ms, or advised or polled tags to be created with a scan rate faster than 500 ms.
Provide Feedback
Have questions or feedback about this documentation? Please submit your feedback here.
Normal