Hello All,
I am now using the Perspective Historical Playback module from Ignition Exchange, but the module seem like cannot function smoothly. This is because I put around 200 tags in the param to get the historical value, but it cannot query all the tags in every seconds and show the historical value for every tags in every seconds, so the playback will show not smoothly, some of the tags will get the historical value and some of the tags will not getting any historical value.
I think this is because the system specification not able to support the query process, but i not comfirm on this. Did anybody had used this playback module and faced this issue before? If this issue is causing by the system specification, i hope to get some advise on how to improve the system specification for supporting the query process.
Thanks!
The playback controller pulls 1 minute at a time (by default) of history, and then caches and plays through that minute. It doesn't pull every second. Obviously this could be tuned to fit your application more specifically. Just bear in mind that the more you increase the time the more you will query the database.
If you have multiple clients that are all looking at different data, this could also cause some contention on the database. The 1 minute caching goes to memory in globals, and is shared across all clients, so if multiple clients are pulling the same points they share the same cache.
You may want to run the query by itself to see how long it takes to query the data for that amount of data points. It's possible that when it gets to the end of playback for that minute and it pulls the next minute, it's taking too long, and there's a delay at that point.
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Hi,
Herewith with my some questions about the playback controller :
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If the playback controller pulls 1 minute at a time, so in my situation, i playback and saw not all the tag historical value was showed, do you know what reason causing this happen? Any advise can solved this? or we need to improved the system performance capability?
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Do you know how to modify the playback controller module to make it flexible in choosing time range for the playback start? For example, i need to choose when does it start and when does it stop, not like the default module, i only can choose 1 minute, 1 hour and 1 day.
Sorry for troublesome you, because i am new to Ignition, so i hope you can help me and give some advise. Hope to hear from you soon! Thanks.
Without seeing your setup, I'm not sure what is causing no history to be shown. You should be able to add the tag to the "tags" parameter to include it in the playback controller. It's possible you need to enable history on those tags or pass in additional tag paths that you want to see that data for. It could be system performance as well, like you mentioned. You would be able to tell how healthy your system is performing on the status page of the gateway. From there you could dive into database connections to see more details on querying historical data from the database.
The main logic for this resource is on the view's custom property "tick" change script. You can tweak the script in there for functionality specific to your implementation. This is definitely not an easy place to start in Ignition so if you need help with scripting within the platform, check out Inductive University's scripting videos.