# Chrono/GPUSPH Communication

**URL:** https://gpusph.discourse.group/t/chrono-gpusph-communication/212
**Category:** Applications
**Created:** [June 18, 2024, 9:22pm UTC](https://gpusph.discourse.group/t/chrono-gpusph-communication/212 "2024-06-18T21:22:28Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![Ethan\_Evans](https://yyz2.discourse-cdn.com/free1/user_avatar/gpusph.discourse.group/ethan_evans/32/141_2.png) [@Ethan\_Evans](https://gpusph.discourse.group/u/Ethan_Evans)
#### Post date: [June 18, 2024, 9:22pm UTC](https://gpusph.discourse.group/t/chrono-gpusph-communication/212/1 "2024-06-18T21:22:28Z")

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Hi,

I am investigating some issues with joints defined in chrono and was wondering about the coupling sequence between Chrono and GPUSPH. How often is information passed to/from chrono? And is that a parameter we can change? (similar to simparams()-\>buildneibsfreq)

Thanks!  
Ethan

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### Author: ![vito.zago](https://yyz2.discourse-cdn.com/free1/user_avatar/gpusph.discourse.group/vito.zago/32/30_2.png) [@vito.zago](https://gpusph.discourse.group/u/vito.zago)
#### Post date: [June 25, 2024, 8:13am UTC](https://gpusph.discourse.group/t/chrono-gpusph-communication/212/2 "2024-06-25T08:13:08Z")

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Hi Ethan,

The Chrono model is integrated with a single step during the SPH predictor (see fea\_do\_step in src/ProblemCore.cc). This single step can even cover multiple SPH steps, and you can set this by using the simparam feaSph\_iterations\_ratio.

Hope this helps,  
Vito