# OPC UA Server Update Rate

**URL:** <https://forum.inductiveautomation.com/t/opc-ua-server-update-rate/41228>\
**Category:** Ignition\
**Created:** [December 4, 2020, 10:34pm UTC](https://forum.inductiveautomation.com/t/opc-ua-server-update-rate/41228 "2020-12-04T22:34:37Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![sydney.bergeron](https://avatars.discourse-cdn.com/v4/letter/s/779978/32.png) [@sydney.bergeron](https://forum.inductiveautomation.com/u/sydney.bergeron)\
**Post date:** [December 4, 2020, 10:34pm UTC](https://forum.inductiveautomation.com/t/opc-ua-server-update-rate/41228/1 "2020-12-04T22:34:37Z")

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What is the tag update rate on the OPC UA Server?  
Does it depend on the Driver (e.g. Allen Bradley Driver)?

For a SQL bridge transaction group, what is the limit on the update rate? It seems like I can make it as fast as I wan to.

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**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [December 4, 2020, 10:38pm UTC](https://forum.inductiveautomation.com/t/opc-ua-server-update-rate/41228/2 "2020-12-04T22:38:33Z")

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There is no fixed update rate, it depends on what the client requests.

When Ignition is the client it uses the rate of the scan class / tag group as the sampling interval for items belonging to the subscription.

There’s a lower limit to sampling intervals that depends what version of Ignition you are using but there is no limit on how fast a read or polled-mode scan class, tag group, or transaction group can attempt to read.

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<div class="post-metadata">

**Author:** ![sydney.bergeron](https://avatars.discourse-cdn.com/v4/letter/s/779978/32.png) [@sydney.bergeron](https://forum.inductiveautomation.com/u/sydney.bergeron)\
**Post date:** [December 7, 2020, 2:19pm UTC](https://forum.inductiveautomation.com/t/opc-ua-server-update-rate/41228/3 "2020-12-07T14:19:44Z")

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Thanks, Kevin.

I’m using Ignition V 8.0.14, do you know the sampling interval for this version?  
Presumably if you attempted to read faster than this in a transaction group, it would just read as fast as it could?

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<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [December 7, 2020, 2:23pm UTC](https://forum.inductiveautomation.com/t/opc-ua-server-update-rate/41228/4 "2020-12-07T14:23:16Z")

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Ignition 8+ doesn't have a minimum sampling interval, it will let you create monitored items with as fast a sampling interval as you'd like to try.

> [@sydney.bergeron](#):
>
> Presumably if you attempted to read faster than this in a transaction group, it would just read as fast as it could?

Yeah, that's pretty much how it works both in and out of subscription groups.