Author Topic: J1939 Receiving Large Message (EC, FEE3)  (Read 10041 times)

Offline AlbertMilani

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J1939 Receiving Large Message (EC, FEE3)
« on: January 10, 2023, 01:54:06 AM »
Hi,

Does anyone have any sample code for receiving large J1939 message that make up more than one packet?  I can't even see how where to start with this.  I've successfully sent and received smaller messages.

I specifically am trying to get the EC, FEE3 message which has 8*7 bytes of data.

Thanks,
Albert

Offline AlbertMilani

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Re: J1939 Receiving Large Message (EC, FEE3)
« Reply #1 on: January 10, 2023, 10:07:25 PM »
I just realized that
Topic: PGN 65259 SPN 588
https://www.plus1forum.danfoss.com/index.php?topic=1585.0
addresses my question but for a different PGN.

I'll try it soon and report back.

Albert

Offline AlbertMilani

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Re: J1939 Receiving Large Message (EC, FEE3)
« Reply #2 on: January 13, 2023, 02:44:40 PM »
I tried the same code from that other topic: PGN 65259 SPN 588 but I'm not seeing any attempts from the engine to send the info.  On the CAN monitor, I see my request which is similar to another request I'm making for a simple PGN that is working but the engine seems to be making no attempt to respond to the request for the large message - I don't see any EB00 packets:

Here's my request where I see it working for the simple PGN; note that I tried a different PGN, FEE3 since FEEB, 65259 wasn't working:
Code: [Select]
0    18EA002C X       3  E5  FE  00                              6.484 R
0    18EA002C X       3  E3  FE  00                              6.500 R
 ...
0    18FEE500 X       8  63  00  00  00  FF  FF  FF  FF          6.515 R

After my request for the large message PGN, should I see something like this on the CAN bus?:
Code: [Select]
0    1CEB002C X       8  01  XX  XX  ...

Thanks,
Albert

P.S.: This is not working for two different engines.
« Last Edit: January 13, 2023, 02:49:22 PM by AlbertMilani »

Offline PosFdbk~~~~~

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Re: J1939 Receiving Large Message (EC, FEE3)
« Reply #3 on: February 14, 2023, 05:24:19 PM »
What is in the rest of your code?  The way the Rx block work, they "absorb" the message.  If this is added after say a DM1 Rx, it will never see the TP messages because they are already taken by DM1.   You basically have to have a central TP receiver that then distributes to places where it is used.

Anyhow, sorry for digging up an old thread, hope you solved the problem!

Offline AlbertMilani

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Re: J1939 Receiving Large Message (EC, FEE3)
« Reply #4 on: February 23, 2023, 05:30:52 PM »
So I can't simply use two simple multipacket message handler function blocks like DM1_Rx1 and even DM2_Rx1 in the same application?!

I was assuming when I got back to this, I'd be able to just make the Enable input false at different times but now I see these blocks don't have them!  What if I lied about the engine address to effectively disable them?  This would be ugly but so much easier.

> You basically have to have a central TP receiver that then distributes to places where it is used.
Should I be able to connect a few parsers to the same TP_RTS_CTS_Rx block?  And send different requests at different times?

> Anyhow, sorry for digging up an old thread, hope you solved the problem!
No apology is needed especially since I didn't solve my problem yet.

Thanks!
Albert
« Last Edit: February 23, 2023, 05:33:48 PM by AlbertMilani »

Offline PosFdbk~~~~~

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Re: J1939 Receiving Large Message (EC, FEE3)
« Reply #5 on: February 23, 2023, 09:24:37 PM »
I think it is easier than that...  The stuff like DM1, DM2, CI, I believe gets blasted out globally with a BAM (even if it is a PGN like DM2 or CI that must be requested with PGN 59904 RQST).  I don't think you'll ever need RTS/CTS.

Anyway, you just hook up BAM to the CI and DTC parsers (Same BAM goes to multiple parsers).

For the "single packet" just hook up the generic PGN_Rx block.  One each to each parser.

Through in the RQST block and you can basically do this all with existing blocks.  I could probably pull together a screenshot for you if needed.

Offline Matt_Eng

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Re: J1939 Receiving Large Message (EC, FEE3)
« Reply #6 on: February 24, 2023, 03:00:05 PM »
Hi, there is actually an example included in the Update Center that shows a setup with a DM1, DM2, and a CI message being received.
It can be found under Files->Applications->PLUS+1 GUIDE examples->J1939_Example
When you download it, you'll find an scs file in the download directory that you can view and even copy.

The newer RTS_CTS + BAM setup is a little more confusing than just dropping in a DM1 or DM2 block, but in order to correctly support multi-packet messaging and satisfy J1939-82 compliance testing it was necessary.

Offline AlbertMilani

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Re: J1939 Receiving Large Message (EC, FEE3)
« Reply #7 on: March 13, 2023, 05:56:32 PM »
Hi,

I got it working using the example (PLUS+1 GUIDE examples->J1939_Example) that Matt_eng recommended! It wasn't too bad after all.

Sorry, I took so long to get back to this; I had some more urgent things to fix.

Thanks!
Albert

Offline macbahi

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Re: J1939 Receiving Large Message (EC, FEE3)
« Reply #8 on: March 14, 2023, 02:02:04 PM »
Hi!

I am interesting to see J1939 example but I didn't find it in my update center.

Please you can see my image of my Plus+1 Update center.

Thank you very much

With best regards


Offline acmall

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Re: J1939 Receiving Large Message (EC, FEE3)
« Reply #9 on: March 15, 2023, 09:27:51 AM »
Mine looks like the attached image. Update Centre version is 1.0.155.4923

Offline nikomas

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Re: J1939 Receiving Large Message (EC, FEE3)
« Reply #10 on: February 20, 2024, 02:44:14 PM »
Hi,

I have downloaded PLUS+1 GUIDE examples->J1939_Example from Update Centre 1.0.167. and implemented it in order to
receive DM01, DM02, CI and VI messages. Messages are time triggered and sent from PCAN application.
Local address is "5" (DM430 display) and source address "0".
I can receive DM01 and DM02 messages but nothing I can see on RTS_CTS_Msg bus on the checkpoints and on checkpoint after CI_Parse block.
If someone can help I will be very grateful.

Best regards,
« Last Edit: February 21, 2024, 08:47:11 AM by nikomas »