Retransmit of CAN

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embtechnicalservices
Posts: 52
Joined: Fri Jan 15, 2016 10:14 am

Retransmit of CAN

Post by embtechnicalservices » Mon Jun 19, 2017 2:54 pm

Hi, a quick question that I cant seem to find an answer to I hope someone could help please?

I can receive and display J1939 messages OK and send out back out fixed value can data. but Is it possible re transmit a J1939 message with a new source address yet with the same data as the received message without using a script?

basically to spoof another device that needs is expecting the data from another transmitter that is not present.
http://www.emb-technical-services.co.uk
Image
Windows 10 Home x64 - PowerVision 2.9.21075 OEM
i7-7700HQ ,16GBRAM, 500GBSSD, DELL Inspion 7567, 4K UHD Display.
boyce
Enovation Controls Development
Enovation Controls Development
Posts: 322
Joined: Wed Sep 08, 2010 5:09 pm

Re: Retransmit of CAN

Post by boyce » Mon Jun 19, 2017 3:47 pm

Yes, it can be done with a Free Form message and an event.

The message that is read from source address 0. The read complete event calls the SpoofEvent to transmit the message.
spoof1.JPG
spoof1.JPG (123.74 KiB) Viewed 117 times
The spoof message from source address 1 with the same variables that were read in.
spoof2.JPG
spoof2.JPG (121.75 KiB) Viewed 117 times
SpoofEvent just transmits the spoof message.
spoof3.JPG
spoof3.JPG (98.41 KiB) Viewed 117 times
Both variables V1 and V2 are defined the same way.
spoof4.JPG
spoof4.JPG (105.39 KiB) Viewed 117 times
There is no message buffering so the message needs to be transmitted before the next message is read.
Boyce Schrack
Enovation Controls
embtechnicalservices
Posts: 52
Joined: Fri Jan 15, 2016 10:14 am

Re: Retransmit of CAN

Post by embtechnicalservices » Tue Jun 20, 2017 5:19 pm

PERFECT! many thanks Boyce.
http://www.emb-technical-services.co.uk
Image
Windows 10 Home x64 - PowerVision 2.9.21075 OEM
i7-7700HQ ,16GBRAM, 500GBSSD, DELL Inspion 7567, 4K UHD Display.
embtechnicalservices
Posts: 52
Joined: Fri Jan 15, 2016 10:14 am

Re: Retransmit of CAN

Post by embtechnicalservices » Wed Jul 05, 2017 3:48 am

HI Boyce,

this works nicely for the same data, we have a new challenge today;

Is there also a method to read in data but break down each byte to a variable that can be changed in powervision based on some other user action, then re packed as a complete message and sent back out.?

thanks, Dave.
http://www.emb-technical-services.co.uk
Image
Windows 10 Home x64 - PowerVision 2.9.21075 OEM
i7-7700HQ ,16GBRAM, 500GBSSD, DELL Inspion 7567, 4K UHD Display.
boyce
Enovation Controls Development
Enovation Controls Development
Posts: 322
Joined: Wed Sep 08, 2010 5:09 pm

Re: Retransmit of CAN

Post by boyce » Thu Jul 06, 2017 11:10 am

Yes, the Free Form CAN message can be defined with 8 bit values that are assigned to the variables. There will be one message that is receive and another one to transmit. Just set the value of the transmit variables as needed and transmit.
ffbytes.JPG
ffbytes.JPG (132.04 KiB) Viewed 91 times
Boyce Schrack
Enovation Controls
embtechnicalservices
Posts: 52
Joined: Fri Jan 15, 2016 10:14 am

Re: Retransmit of CAN

Post by embtechnicalservices » Thu Jul 06, 2017 12:23 pm

super, thanks Boyce.
http://www.emb-technical-services.co.uk
Image
Windows 10 Home x64 - PowerVision 2.9.21075 OEM
i7-7700HQ ,16GBRAM, 500GBSSD, DELL Inspion 7567, 4K UHD Display.