flexray 发送ID

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flexray 发送ID

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sdm
Contributor I

MC9S12XF512MLM芯片在用官方例程更改flexray发送帧ID值超过100后无法正常发送需要更改那些配置

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lama
NXP TechSupport
NXP TechSupport

Hi,

 

FlexRay allows many configuration options and at the same time the individual configuration parameters are quite interconnected. If the customer sends a request that he wants to send in slot 100 and at the same time the payload needs to be changed, it means to make a new configuration of the communication cycle, which already requires some knowledge of the FlexRay protocol.

 

We can try to answer the following, where we will outline what the customer should change, but if the customer does not understand the FlaxRay protocol, it will be very difficult with any additional support.

 

FlexRay configuration is very variable and you can adopt communication cycle exactly for your purposes but this requires more detailed knowledge of the FlexRay Protocol specification. Thus we can provide you basic information how the communication cycle used in our FlexRay UNIFIED driver example is configured:

 

Unified Driver is configured as follows: (Please, see, Fr_UNIFIED_cfg.c file where you can find yellow labeled configuration parameters.)

 

gdCycle=5ms (G_MACRO_PER_CYCLE=5000)

gdStaticSegment=(G_NUMBER_STATIC_SLOTS * GD_STATIC_SLOT)=60*50=3000 (3ms)

gdDynamicSegment=(G_NUMBER_OF_MINISLOTS * GD_MINISLOT)=22*40=880

gdSymbolWindow=(GD_SYMBOL_WINDOW)=13

gdNIT=gdCycle-(gdStaticSegment+gdDynaicSegment+gdSymbolWindow)=5000-(3000+880+13)=1107

 

In our example Frames IDs <1,60> will be transmitted in static segment and Frames IDs <61,82> in dynamic segment.

 

 

lama_0-1650375185610.png

 

 

 

How to change the ID range?”

  • You can change either G_NUMBER_STATIC_SLOTS or G_NUMBER_OF_MINISLOTS depending on used segment, but you must ensure that equation above is always valid!
  •  

“How to change data length of data in static and dynamic segment?

  • Static segment -  change G_PAYLOAD_LENGTH_STATIC configuration parameter and please see FlexRay Protocol Specification for more details. Caution! This parameter is limited by GD_STATIC_SLOT parameter.
  • Dynamic Segment – change P_PAYLOAD_LENGTH_DYN_MAX and please see FlexRay Protocol Specification for more details.

 

Caution! Configuration parameters with G_ & GD_ prefixes must be changed in all FlexRay nodes connected to one cluster!!!

Best regards,

Ladislav

 

 

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sdm
Contributor I

请问gdNIT是需要更改的还是自动计算生成了,我在配置文件中并没有找到这一参数

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lama
NXP TechSupport
NXP TechSupport

Hi,

the support of this device and SW related to it is limited. However, I have an info from one guy who has some knowledge about the topic. His response was:

”I would ask if the Frame ID is not higher than, for example, gNumberOfStaticSlots or gNumberOfMinislots, which are configuration parameters that define the number of time slots in a communication cycle.”

Best regards,

Ladislav

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1,119 Views
sdm
Contributor I

目前G_NUMBER_OF_MINISLOTS值为22,但是当我更改为其他数值时就无法发送了

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