A problem about the Sample Time in the asynchronous subsystem

w w
2011 11 18
2 个回答
回答已采纳
5 次查看（30 天）

0 个投票

Hi, There is a subsystem in my model.The model's sample time is 0.0001,and i want to set some block's sample time in the subsystem 0.0005.But when i click the build button ,i got the error as follows:
Error building Real-Time Workshop target for block diagram '2812_StepTime'. MATLAB error message: '2812_StepTime/Function-Call Subsystem/Counter Limited/Output' has an invalid sample time. Only constant (inf) or inherited (-1) sample times are allowed in the asynchronous subsystem '2812_StepTime/Function-Call Subsystem/Counter Limited'
How could solve this problem?
My matlab version: 2009a
Best regards.

请先登录，再回答此问题。

 采纳的回答

Titus Edelhofer
Titus Edelhofer 2011-11-18

1 个投票

Hi,
this can't work: you call you subsystem with a function call asynchronously, so blocks inside the subsystem have no "direct" control about when the subsystem is called. How could a block inside impose a sample time? It would need to carry this information to the containing subsystem... Perhaps you could explain in more detail why a block inside the fcn call subsystem should have a fixed sample time...
Titus

2 个评论
显示 无 隐藏 无

w w
w w 2011-11-18
The subsystem is called by a Hardware Interrupt block.If the blocks in the subsystem should be with different,is there any ways to solve ths situation?
Titus Edelhofer
Titus Edelhofer 2011-11-18
One way to overcome many problems: move the offending block outside the subsystem and feed the output of the block as an input to the subsystem (probably using a rate transition block in between). Further advice is I guess only possible with more information aout why you want to have a fixed sample time block in your subsystem.

请先登录，再进行评论。

更多回答（1 个）

Fangjun Jiang
Fangjun Jiang 2011-11-18

0 个投票

It makes sense, right? Your "2812_StepTime/Function-Call Subsystem/" is a function-call system, which could be called irregularly, depending on where the function call trigger comes from. Thus, it can not guarantee the inside block "Counter Limited/Output" be called in a fixed rate.
It sounds like you are using a function call generator block with a fixed sample rate. Why not try to specify your subsystem as an atomic subsystem with a fixed sample rate of 0.0001. I believe that will get rid of the error.

1 个评论
显示 -1更早的评论 隐藏 -1更早的评论

w w
w w 2011-11-18
The subsystem is called by a Hardware Interrupt block.So i could not use the atomic subsystem.

请先登录，再进行评论。

类别

在 帮助中心 和 File Exchange 中查找有关 Subsystems 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by