Hi all, we have a data collection for multiple sites connected through VPN. It started with one single IG server with tags defined in the central ‘tag provider’. I grouped tags in different Local tag providers, each named differently as the plant name from where the tags are.
The historian is on the central IG server connection.
We need to define TPA tag provider as a 'Remote tag provider' and delete the TPA 'Local Tag Provider'.
Is there a way to have no discontinuity on history for tags [TPA]TAG_1 and [TPA]TAG_2?
Any experience on that?
I hope I am understanding this correctly you have IG server with tags and you have created group tags in the different local tag providers you are trying to move these tags to the internal gateway for different plants but you want to continue using the IG server to store history?
If this is the case, then you could just move the tags to the IG via exporting them then importing them to those plants Internal gateways and then change their history setting to that the tags are storing tag history via the remote tag history provider that is on the Central server. If you have any scripts that reference local gateway that should be changed to reference the remote tag provider. Then you may be able to delete the local provider.
Thanks anjoroge, sorry if I expressed my needing unclearly.
you have created group tags in the different local tag providers you are trying to move these tags to the internal gateway for different plants
Now I have the TAG defined in the central location and I enabled the historian on the central IG. I defined on the central IG a tag provider for each plant. I need to move the TAGs to remote local plants' IG so that the central IG will receive values from plants' Remote Tag Provider.
I need to keep the historian on the central server AND maintain the continuity of data (before and after the move).
As far as I know, IG change the tag_id on historian if I move a TAG from standard Local provider to Remote Provider and this will disrupt the continuity of historian.
Yes. You will need to transfer the data manually, or, perhaps, alter the meta-data manually. (The latter will require historian restart, as metadata is cached.)
Thanks @pturmel, it's a honor for me to receive your comment.
Sorry if I am writing a bit wordy.
I am going to:
use Gateway Events (Tag Change) on the central IG to save tags values into a custom DB
(a week later) bind graphs and other graphics controls to this "custom" historian. This would be a seamless experience for users.
When a plant will install IG locally we will:
3) create on local plant's IG a Gateway Events (Tag Change) script to store tag values on a local DB (to create a temporary local queue).
4) write a queue manager on central IG to consume the remote plant's "temporary queue" and write values to the central IG DB and finally
5) disable the scripts created at step1.
I have read some post of yours where you suggest to use Store&Forward to write tag values into DB in the Tag Change scripts because of limited script threads. Do you thing it's a good idea to use S&F in this case, too?
At the end we will:
a) have network connection resilience (during a network failure of plants data stay on DBs and later queue will be consumed by 4),
b) control of remote DB queue dimensions,
c) keep continuity on tag value history before and after a remote plant IG installation
We are reinventing the wheel, I know, but I feel more confortable to have the complete ownership of the system.
Thanks in advance for any answer from you or any suggestion from the IA Crew.
Enrico
I would not do this. Learn the schema for the historian so you can manipulate it when you move tags.
Learn to use explicit history paths with remote tag providers to avoid querying through the GAN. (Best when combined with native DB replication from remote to central.)
