# Hi, how do I create timer based on certain voltage only

**URL:** <https://discourse.nodered.org/t/hi-how-do-i-create-timer-based-on-certain-voltage-only/12550>\
**Category:** Dashboard\
**Created:** [24 June 2019 15:16 UTC](https://discourse.nodered.org/t/hi-how-do-i-create-timer-based-on-certain-voltage-only/12550 "2019-06-24T15:16:17Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![afiqkimii](https://avatars.discourse-cdn.com/v4/letter/a/e9bcb4/32.png) [@afiqkimii](https://discourse.nodered.org/u/afiqkimii)\
**Post date:** [24 June 2019 15:16 UTC](https://discourse.nodered.org/t/hi-how-do-i-create-timer-based-on-certain-voltage-only/12550/1 "2019-06-24T15:16:17Z")

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Im doing maintenance calling system project.I want the timer to start counting after the voltage exceeds certain limit.Is that possible?  
I have 4 input using modbus and switches.After clicking respective switches the voltage will rise to a certain level.I want the timer to start counting after I clicked the switches.How do I do this?  
Already searched on youtube but they only uses inject not voltage as my project.  
How?  
Thanks!  
Kimi,

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**Author:** ![ukmoose](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ukmoose/32/13_2.png) [@ukmoose](https://discourse.nodered.org/u/ukmoose)\
**Post date:** [24 June 2019 15:27 UTC](https://discourse.nodered.org/t/hi-how-do-i-create-timer-based-on-certain-voltage-only/12550/2 "2019-06-24T15:27:56Z")

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What have you done so far?

You can store a time within a context value ( see the documentation on function nodes for an explanation)

The cookbook is also worth looking at [http://cookbook.nodered.org](http://cookbook.nodered.org)

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<div class="post-metadata">

**Author:** ![afiqkimii](https://avatars.discourse-cdn.com/v4/letter/a/e9bcb4/32.png) [@afiqkimii](https://discourse.nodered.org/u/afiqkimii)\
**Post date:** [27 June 2019 06:52 UTC](https://discourse.nodered.org/t/hi-how-do-i-create-timer-based-on-certain-voltage-only/12550/3 "2019-06-27T06:52:00Z")

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Alright thanks bro , ill study the the links. Thanks a lot