# SFC Charts, Sleep Timers, and Threads

**URL:** <https://forum.inductiveautomation.com/t/sfc-charts-sleep-timers-and-threads/73346>\
**Category:** Ignition\
**Created:** [May 5, 2023, 8:59pm UTC](https://forum.inductiveautomation.com/t/sfc-charts-sleep-timers-and-threads/73346 "2023-05-05T20:59:17Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![grietveld](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/grietveld/32/6984_2.png) [@grietveld](https://forum.inductiveautomation.com/u/grietveld)\
**Post date:** [May 5, 2023, 8:59pm UTC](https://forum.inductiveautomation.com/t/sfc-charts-sleep-timers-and-threads/73346/1 "2023-05-05T20:59:17Z")

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Finally found a project that I get to explore SFC charts a bit more and have a question for those who may have explored a bit deeper than I have so far. Building some charts to manage a Test stations sequence for calling sequences of WebAPI calls. In some cases I need to keep polling until my data set is built or the test completed.

Is it safe to use sleep timers in the SFC chart? Or is there a better way to handle this? I don't want to overload the webserver sending too many requests, but I also know sleep timers can cause bottlenecks elsewhere in Ignition. There should only be 2 instances of this chart running maximum at any given time on the gateway.

Thanks in advance!

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**Author:** ![Gabriel\_Hernandez](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/gabriel_hernandez/32/47179_2.png) [@Gabriel\_Hernandez](https://forum.inductiveautomation.com/u/Gabriel_Hernandez)\
**Post date:** [May 12, 2023, 10:20pm UTC](https://forum.inductiveautomation.com/t/sfc-charts-sleep-timers-and-threads/73346/2 "2023-05-12T22:20:43Z")

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Hi,

Here is an excerpt from our user manual page that goes over pitfalls of using sleep timers and reasons to avoid them:  
[Adding a Delay to a Script - Reasons to Avoid time.sleep and While Loops](https://docs.inductiveautomation.com/display/DOC81/Adding+a+Delay+to+a+Script#AddingaDelaytoaScript-ReasonstoAvoidtime.sleepandWhileLoops)

I think you might find [SFC Elements - Timer](https://docs.inductiveautomation.com/display/DOC81/SFC+Elements#SFCElements-Timer) helpful. As a bonus, there is a nifty Inductive University video that supplements the information in the SFC Elements page.  
I would also recommend watching the other SFC videos on Inductive University to bolster your knowledge.