# \[Question\] How do I use .readAsync to read tag value

**URL:** <https://forum.inductiveautomation.com/t/question-how-do-i-use-readasync-to-read-tag-value/22008>\
**Category:** Ignition Early Access\
**Created:** [January 21, 2019, 12:10am UTC](https://forum.inductiveautomation.com/t/question-how-do-i-use-readasync-to-read-tag-value/22008 "2019-01-21T00:10:44Z")\
**Posts on this page:** 1\
**Showing post:** 7

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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:** [March 5, 2019, 4:59pm UTC](https://forum.inductiveautomation.com/t/question-how-do-i-use-readasync-to-read-tag-value/22008/7 "2019-03-05T16:59:42Z")

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You can make semi-generic callbacks by creating jython classes that implement the ` __callable__ ` special method, and supply an instance as the callback. Have the ` __init__ ` method save the state you need to carry your logic forward.

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