# How to trap the "Unknown" tag quality

**URL:** <https://forum.inductiveautomation.com/t/how-to-trap-the-unknown-tag-quality/10681>\
**Category:** General Discussion\
**Created:** [October 27, 2015, 3:44pm UTC](https://forum.inductiveautomation.com/t/how-to-trap-the-unknown-tag-quality/10681 "2015-10-27T15:44:49Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![pgmo](https://avatars.discourse-cdn.com/v4/letter/p/d07c76/32.png) [@pgmo](https://forum.inductiveautomation.com/u/pgmo)\
**Post date:** [October 27, 2015, 3:44pm UTC](https://forum.inductiveautomation.com/t/how-to-trap-the-unknown-tag-quality/10681/1 "2015-10-27T15:44:49Z")

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I have many Numeric Text Fields on a window, whose PropertyChange event I use to do some special logging. Their “Double Value” properties area linked to the fields of some UDT variables, which get their values from a Kepware OPC UA Server. When I open that window the very first time after Ignition start, the unknown quality overlay appears and a -1 gets logged to my database. Is there no way to understand the quality of the event.newValue in the PropertyChange event, so that I can discard all bad quality values?

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**Author:** ![jim\_lapratt](https://avatars.discourse-cdn.com/v4/letter/j/cc9497/32.png) [@jim\_lapratt](https://forum.inductiveautomation.com/u/jim_lapratt)\
**Post date:** [October 29, 2015, 11:28am UTC](https://forum.inductiveautomation.com/t/how-to-trap-the-unknown-tag-quality/10681/2 "2015-10-29T11:28:47Z")

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If all you want is the good quality tags you can filter data on tag quality 192

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**Author:** ![pgmo](https://avatars.discourse-cdn.com/v4/letter/p/d07c76/32.png) [@pgmo](https://forum.inductiveautomation.com/u/pgmo)\
**Post date:** [October 29, 2015, 12:06pm UTC](https://forum.inductiveautomation.com/t/how-to-trap-the-unknown-tag-quality/10681/3 "2015-10-29T12:06:02Z")

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Thank you jim\_lapratt. Yes I want that, but I want to catch it in the PropertyChange event, where, as far as I know, you only get the event.newValue field, but you know nothing about the quality of that newValue.

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**Author:** ![JordanCClark](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jordancclark/32/83362_2.png) [@JordanCClark](https://forum.inductiveautomation.com/u/JordanCClark)\
**Post date:** [October 29, 2015, 12:14pm UTC](https://forum.inductiveautomation.com/t/how-to-trap-the-unknown-tag-quality/10681/4 "2015-10-29T12:14:09Z")

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You would want to grab the value of the Data Quality property of the component.

```auto
event.source.dataQuality
```