# \[SOLVED\] How often does the System tags get refreshed?

**URL:** <https://forum.inductiveautomation.com/t/solved-how-often-does-the-system-tags-get-refreshed/56473>\
**Category:** Ignition\
**Tags:** vision, ignition81, scripting\
**Created:** [February 23, 2022, 7:16pm UTC](https://forum.inductiveautomation.com/t/solved-how-often-does-the-system-tags-get-refreshed/56473 "2022-02-23T19:16:57Z")\
**Posts on this page:** 8\
**Page:** 1

<div class="post-metadata">

**Author:** ![bmeyers](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/bmeyers/32/37453_2.png) [@bmeyers](https://forum.inductiveautomation.com/u/bmeyers)\
**Post date:** [February 23, 2022, 7:16pm UTC](https://forum.inductiveautomation.com/t/solved-how-often-does-the-system-tags-get-refreshed/56473/1 "2022-02-23T19:16:57Z")

</div>

My evidence suggests it gets refreshed every 5 minutes but how do I prove that? I am using the tag

```auto
[System]Client/Network/Hostname
```

in an expression and every 5 minutes that expression is firing off. The only thing I can think of is the expression thinks it is being updated (even though the value is always the same).

Anyone care to chime in?

---

<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [February 23, 2022, 9:39pm UTC](https://forum.inductiveautomation.com/t/solved-how-often-does-the-system-tags-get-refreshed/56473/2 "2022-02-23T21:39:50Z")

</div>

It’s on a five minute poll, yes. The system tags don’t do any actual logic to push out changes, I’m guessing, so every value refresh fires a new event which triggers your expression downstream.

---

<div class="post-metadata">

**Author:** ![bmeyers](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/bmeyers/32/37453_2.png) [@bmeyers](https://forum.inductiveautomation.com/u/bmeyers)\
**Post date:** [February 23, 2022, 10:29pm UTC](https://forum.inductiveautomation.com/t/solved-how-often-does-the-system-tags-get-refreshed/56473/3 "2022-02-23T22:29:49Z")

</div>

Interesting. Based on my previous understanding of expressions I would have thought this was impossible since the value never changed. It was quite the mystery for a while.

---

<div class="post-metadata">

**Author:** ![dkhayes117](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/dkhayes117/32/68344_2.png) [@dkhayes117](https://forum.inductiveautomation.com/u/dkhayes117)\
**Post date:** [February 23, 2022, 10:34pm UTC](https://forum.inductiveautomation.com/t/solved-how-often-does-the-system-tags-get-refreshed/56473/4 "2022-02-23T22:34:11Z")

</div>

The tag values are fully qualified, so if you are not looking at the just the value, an update with the same value will fire a tag change event because the timestamp changed.

---

<div class="post-metadata">

**Author:** ![bmeyers](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/bmeyers/32/37453_2.png) [@bmeyers](https://forum.inductiveautomation.com/u/bmeyers)\
**Post date:** [February 23, 2022, 10:42pm UTC](https://forum.inductiveautomation.com/t/solved-how-often-does-the-system-tags-get-refreshed/56473/5 "2022-02-23T22:42:42Z")

</div>

Aren’t regular tags fully qualified?

---

<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [February 23, 2022, 10:56pm UTC](https://forum.inductiveautomation.com/t/solved-how-often-does-the-system-tags-get-refreshed/56473/6 "2022-02-23T22:56:31Z")

</div>

> [@bmeyers](#):
>
> Based on my previous understanding of expressions I would have thought this was impossible since the value never changed.

The expression doesn't "know" what was delivered, only that a new value _was_. In most contexts in Ignition (e.g. Vision), for optimization and other reasons, "matching" events aren't sent through. It would be possible to update the system tags to do the same thing, but it's _probably_ not worth the effort (and potential risk; see: [Hyrum's Law](https://www.hyrumslaw.com/)).

---

<div class="post-metadata">

**Author:** ![bmeyers](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/bmeyers/32/37453_2.png) [@bmeyers](https://forum.inductiveautomation.com/u/bmeyers)\
**Post date:** [February 24, 2022, 2:34pm UTC](https://forum.inductiveautomation.com/t/solved-how-often-does-the-system-tags-get-refreshed/56473/7 "2022-02-24T14:34:01Z")

</div>

That is a GOOD law… I would just insist that this particular feature of system tags be documented somewhere for the next person.

---

<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:** [February 24, 2022, 2:44pm UTC](https://forum.inductiveautomation.com/t/solved-how-often-does-the-system-tags-get-refreshed/56473/8 "2022-02-24T14:44:50Z")

</div>

I think this odd behavior is unique to _Client_ system tags… it doesn’t sound quite right to me for Gateway system tags.