Cannot send/receive messages to my CAN controller

[roboter]

I have recently purchased the adapter. I have a microcontroller with CAN controller setup with 2 different microcontrollers. One setup is with Arduino+MCP CAN controller and the other one with Microchip ATSAME51 MCU with on-board CAN controller. I have established a successful network with 2 Arduinos and 2 ATSAME51, where I can transmit and receive CAN messages from all nodes.
- However, when I connect the PEAK adapter, I do not see any incoming traffic nor can I transmit the messages from PCAN-View software.
- I tried with different baud rates and I never see any incoming message.
- I have also tried "only incoming" option as well but to no avail.
- The network by default uses 125kbit/s and the Peak adapter has so far never received any message.
- I also connected the ground of my CAN bus to the ground pin of the adapter.

There are not a lot of options to choose from in the PCAN-View software so I request you to suggest me the debug options.

[M.Heidemann]

Helllo,

Please check the following:

Is the CAN-Bus properly terminated (120Ohms) at both Bus-Ends?

If no communication is possible, you should be able to see an error state
in PCAN-View:

PCAN-View Error State.PNG (4.67 KiB) Viewed 6571 times

Whats the feedback from PCAN-View regarding the state?

Does the 125kbit/s configuration match the one used on the other nodes?

You can customize the bitrate-configuration by pressing the "play" symbol in the connection window:

PCAN-ViewC-CustomBitrate.png (79.44 KiB) Viewed 6571 times

Add you custom bitrate using the "Add"-Button:

PCAN-View-AddCustom.png (60.08 KiB) Viewed 6571 times

Make sure use the same bitrate settings as the other nodes and adjust the configuration accordingly (Prescaler, TESG1, TSEG2, SJW):

Also check for the used clock frequency.

lastly, check your cabling for swapped pins or breakage.

Please report back to us regarding this.

Best Regards

Marvin

[roboter]

Hi,

the CAN bus is properly terminated at both ends with 120Ohms.
When I am not transmitting any messages from the PCAN View to my CAN bus, the Status says OK. But when I transmit in cycle, the status changes to BUSHEAVY. But nevertheless, there are no messages being received at any point in this tool.
Yes, both the nodes are configured at 125kbits/s.
The cables are fine and the physical connections seems good.
The issue seems to be the configuration with the correct bitrate settings. Any ideas how I could achieve the correct settings? Would an oscilloscope measurement on the bus help?

[M.Heidemann]

Hello,

You may wanna check, if the PCAN-USB is working as intended by measuring the transceiver voltages, please
see this forum post regarding this:

viewtopic.php?f=120&t=52&p=133&hilit=defective#p133

Also you should try to see, if using a sample-point of 75% at the bitrate of 125k will solve the issue, for this
create a custom bitrate with the following preferences:

PCAN-View_Custom_Bitrate_125_75.PNG (22.76 KiB) Viewed 6550 times

Prescaler: 4

TSEG1: 11

TSEG2: 4

SJW: 3


You can also measure this using a scope, given the Scope is capable of doing so.

Furthermore i assume you currently use a PCAN-USB (IPEH-002021 / IPEH-002022) (White housing),
is this correct?

Please report back to us regarding this.

Best Regards

Marvin

[roboter]

Hi,

thanks for the link. I tried everything on that post. The voltage measurements seems fine. Although, the differential voltages were: CAN H to GND is 2.95V and CAN L to GND is 2.05V.
I tried the 75% sample point and that did not change anything.
I am not quite sure what you suggest using the osci.
And yes, IPEH-002022 is the one I am using.

[M.Heidemann]

Hello,

Do you use any kind of USB-hub or USB-Extension?

If you do, please use your PCAN-USB (IPEH-002022) directly on a USB-Port of your PC.

Furthermore: We do know of modules that claim to use 125Kbit/s but are off by 2-3%
resulting in the bitrate being more in the range of 123kbit/s for example, you should check, if you can establish a connection using slightly higher or lower bitrates, this unfortunately involves trial and error.

As a help you can use the bitrate-calculation-tool:
https://www.peak-system.com/fileadmin/m ... onTool.zip

Choose SJA1000 Bitratte, as the PCAN-USB is a SJA1000 based device.

Follow the instructions given in the tool, we do recommend to stick with the Sample-Point of 75%.

Add the bitrates as described previously and check, if that resolves the issue.

Please give us feedback regarding this.

Best Regards

Marvin