# Ignition 8.0.16 - Status/Tags/Groups Last duration

**URL:** <https://forum.inductiveautomation.com/t/ignition-8-0-16-status-tags-groups-last-duration/38397>\
**Category:** Ignition\
**Tags:** ignition80\
**Created:** [September 4, 2020, 1:04pm UTC](https://forum.inductiveautomation.com/t/ignition-8-0-16-status-tags-groups-last-duration/38397 "2020-09-04T13:04:29Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\
**Post date:** [September 4, 2020, 1:04pm UTC](https://forum.inductiveautomation.com/t/ignition-8-0-16-status-tags-groups-last-duration/38397/1 "2020-09-04T13:04:29Z")

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**Ignition 8.0.16**

On the gateway, in the **Status/Tags/Groups** :  
**Last duration** has no unit and lots of value are 0.

The value are in milliseconds (or seconds) ? rounded ?

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/4/c/4c832c62da47378bb7ac613372dbafa865b523ca.png)

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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:** [September 4, 2020, 1:09pm UTC](https://forum.inductiveautomation.com/t/ignition-8-0-16-status-tags-groups-last-duration/38397/2 "2020-09-04T13:09:27Z")

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It’s all milliseconds, and the during a conversion from nanos to millis for groups that executed effectively instantly some precision is lost. Most tag types no longer contribute to group execution time any more.

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**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\
**Post date:** [September 4, 2020, 1:33pm UTC](https://forum.inductiveautomation.com/t/ignition-8-0-16-status-tags-groups-last-duration/38397/3 "2020-09-04T13:33:06Z")

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Ok,  
But I have **Driven** tag group for tag expression with Last Duration = 0.  
Executions count is incremented, so the expression is active, but the last duration value = 0  
These expression execute **runscript** with quite long task so I supected that the value was not updated in that case…

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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:** [September 4, 2020, 1:35pm UTC](https://forum.inductiveautomation.com/t/ignition-8-0-16-status-tags-groups-last-duration/38397/4 "2020-09-04T13:35:21Z")

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Expression tags in 8 run in a thread pool and their execution time no longer contributes to the group execution.

I think we’ve discussed removing these measurements in 8 because they are effectively useless.

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<div class="post-metadata">

**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\
**Post date:** [September 4, 2020, 1:46pm UTC](https://forum.inductiveautomation.com/t/ignition-8-0-16-status-tags-groups-last-duration/38397/5 "2020-09-04T13:46:17Z")

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Ok I see, with System.currentTimeMillis() I can measure the time in the runscript.  
In 7.9, I checked the Group’s Last Duration to check if the Rate was compatible with the execution time.

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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [September 4, 2020, 1:54pm UTC](https://forum.inductiveautomation.com/t/ignition-8-0-16-status-tags-groups-last-duration/38397/6 "2020-09-04T13:54:19Z")

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Don’t use System.currentTimeMillis() for durations. Use System.nanoTime() instead. It won’t go backwards on you, and is more precise, too.

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<div class="post-metadata">

**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\
**Post date:** [September 4, 2020, 1:59pm UTC](https://forum.inductiveautomation.com/t/ignition-8-0-16-status-tags-groups-last-duration/38397/7 "2020-09-04T13:59:59Z")

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Multiple thread are launched for the same Tag Group or one thread for one Tag group ?

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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:** [September 4, 2020, 3:16pm UTC](https://forum.inductiveautomation.com/t/ignition-8-0-16-status-tags-groups-last-duration/38397/8 "2020-09-04T15:16:25Z")

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All expression tags execute on one shared thread pool.