Hi! All Now I use "CAN" and want to send 8 commands in a program, among which 6 commands have the same frame ID. The following is part of the screenshot of my program. My problem now is that what I read is the result after the execution of the first command, and I want to see the result of the execution of the following commands. If not, do I have to break them down into steps using TestStand?The ID of the third through eighth commands must be 773.My program now has to loop through the first to third commands.Fourth to eighth command, just run it once, so for fourth to eighth command I used a parallel structure. please help me. Thanky you.😭

XNet also handles multiplexed signals fairly well. However I found a few behaviors of it to what I would consider a bug. When I developed the Frame Signal conversion I changed the behavior of these conversions to be in line with what I thought they should be. But still since OP was talking about seeing a response, I suspect they are doing something else like the ISO15765, UDS, KWP2000, or some other command response scheme.

Hi MaSta, @MaSta wrote: The idea of CAN is actually to use different IDs to be able to distinguish messages. CAN allows for "multiplexing" messages. The CAN driver handles such messages by parsing the "multiplexer" value. So one ArbID can be used to transfer a large number of signal values… I had to implement such messages just two weeks ago and now I know the (old) NI-CAN driver handles multiplexed messages off-the-shelf (when the DBC is well-defined)!

The idea of CAN is actually to use different IDs to be able to distinguish messages. If you send out 5 messages to ID 500 and the counterpart would reply using the same ID or a specific ID that is connected to 500, then the replies would also all have the same ID. You couldn't sort of to which of the 5 sent messages which reply belongs. The code you built is also asynchronous. I would do it differently. The loops are only for sending and receiving, they don't define the ID. The ID and the related payload would be placed in variables outside of these two loops. The outer loop would this way define what to send and when.

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If you are doing UDS communication, then you can read up, and look at the examples I linked to earlier. It is not specifically for NI-XNet but shows how you can perform requests and read responses using UDS. If you want to use an official NI toolkit, look into the Automotive Diagnostic Command Set toolkit by NI. It performs UDS communication, either with NI-CAN hardware, or the newer NI-XNet hardware.

@MaSta wrote:

@xiaosanhe1224: if I may add my two cents to the probably still coming answer of GerdW... The multiplexing can be sorted out using a DBC. I personally never worked with CAN under LabVIEW and cannot say that for sure, but I doubt that any VI, no matter if NI-CAN or NI-XNET, has an extra function for multiplexing.

This is incorrect. The XNet database editor allows you to import a DBC, or create one from scratch. From LabVIEW you can reference this database, and read and write muxed signals and the API handles the conversion for you. The Frame Signal conversion code I linked to earlier also handles muxed signals.

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