Hope all is well.
We have DV 11.3.1 , creating new tags , but these tags when added to Process history view, they only show the current values, no past values or past trending.
could be a license issue, we have old tags which show the current and past values on Process history view.
any help appreciated
For history collection to happen for module, there are three steps: Configure the parameters on the module you wish to collect history data for, make sure the module's Plant area is assigned to the Continuous Historian container on the Historian App station (or operator station for that matter), and download the Continuous historian.
Under the module's context menu you can see the configured history tags using the History Collection option
check the assigned Plant Areas under the Continuous Historian container:
And Download the Continuous Historian. Note that downloading setup data or changed setup data does not download the Continuous Historian. After adding a tag for history to a module, and if that module is an assigned area, then the continuous Historian will already indicate a download flag (blue triangle).
If all these things are done, make sure you have downloaded changed setup data to the proplus so that the module is added to the runtime module list shared with all workstations. If the Operator station is able to display data from the module, then this has been done, otherwise you would not receive any data from the module at the consoles.
Finally, you have to be asking for the actual historized path. By default, DeltaV templates use the typical Block/parameter paths suchas MODULE/AI1/OUT.CV, or MODULE/PID1/PV.CV etc. The default PHV files designed to work with the faceplates are configured to these paths. (i.e. @mod@/PID1/PV.CV). The wild card is substituted for the Module name when the PHV Chart is called from the faceplate. If your module has exposed the PID1/PV parameter to a module parameter, such that th historized tag is Module/PV.CV, then it is possible that you are historizing the value, but in your PHV Chart, you are configured to use MODULE/PID1/PV.CV instead of the historized tag.
Check the path of your PHV chart and compare that the History Collection Parameters you have configured on the module. They must match. This too could explain why you see no history on the chart and only real time trending.
Andre Dicaire