# Unable to perform simulation after power module is switched from "switched" to "sub-cycle average"

**URL:** <https://forum.plexim.com/t/unable-to-perform-simulation-after-power-module-is-switched-from-switched-to-sub-cycle-average/1115>\
**Category:** RT Box\
**Created:** [April 14, 2022, 8:38am UTC](https://forum.plexim.com/t/unable-to-perform-simulation-after-power-module-is-switched-from-switched-to-sub-cycle-average/1115 "2022-04-14T08:38:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Teresa](https://avatars.discourse-cdn.com/v4/letter/t/958977/32.png) [@Teresa](https://forum.plexim.com/u/Teresa)\
**Post date:** [April 14, 2022, 8:38am UTC](https://forum.plexim.com/t/unable-to-perform-simulation-after-power-module-is-switched-from-switched-to-sub-cycle-average/1115/1 "2022-04-14T08:38:12Z")

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Hi,

My name is Teresa.

I have done the simulation using the switch configuration of the power module element in the library and it works fine.  
But I want to try to use RTbox to achieve further simulation, which means RTbox is responsible for plant and external control board is responsible for control level. And when I read the user manual I found out that I have to use the “sub-cycle average” mode of the power module to allow high switching frequencies.

However I can’t directly use “sub-cycle average” to implement the simulation, the simulation cannot be executed. Due to the limitation that the upper and lower switches cannot be turned on at the same time, but this has to happen in my application (see attached documentation).

I have been trying to modify the mask under the power module but still can’t solve the problem.

Is there anything I can do to fix this problem?

thank you very much.

Teresa

[PLECS\_sub-cycle.pdf](https://forum.plexim.com/uploads/short-url/e2OqFC1dsbiLfd7VMrd1rva7l8C.pdf) (305 KB)

[[PLECS PSPWM]4Level FCML.plecs](https://forum.plexim.com/uploads/short-url/x0eIGF6EvERezLMTdpcXeWEz7v3.plecs) (49.1 KB)

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**Author:** ![Manu\_Parimi](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/manu_parimi/32/6_2.png) [@Manu\_Parimi](https://forum.plexim.com/u/Manu_Parimi)\
**Post date:** [April 15, 2022, 12:04pm UTC](https://forum.plexim.com/t/unable-to-perform-simulation-after-power-module-is-switched-from-switched-to-sub-cycle-average/1115/2 "2022-04-15T12:04:48Z")

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Hi Teresa,

This question is best suited for Plexim support. Can you please email the same to [support@plexim.com](mailto:support@plexim.com)?

Thanks,  
Manu