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Problems with CAN TX on Nucleo F767ZI

luisegzb
Visitor

Greetings,

I have a project on the Nucleo F767ZI board where I try to send a CAN message to another device (in particular, an Maxon EPOS4 Compact 50/5 drive). I can receive messages from this device with no problem, however, as soon as I press the button to start sending messages from the Nucleo board to that device, the drive enters into fault state, allegedly because of a 'CAN passive mode error', which arises because of a bad network configuration or baud rate setting. The Nucleo can still receive messages with no problem after this happens.I have checked the H/L connections with a scope, and can see that there is data coming from both devices.

 

My setup is as follows:

Hardware Setup:

Nucleo board connected to CAN_H/_L through a TJA1050 transceiver board (schematic attached)
120 Ohm termination resistor in both the TJA board as well in the other device (resistor in the EPOS drive). I get a 60 Ohm reading between H and L when using a multimeter, as expected.
Connected device powered by an external supply, however both GNDs are connected (continuity test + correct voltage readings).


Board configuration:

- CAN: 125kbps baud rate, 13 bit quanta for seg. 1 and 2 for seg. 2 (calculated to get a 87.5% sample, following CANOpen specification)

- Clock: 200MHz

To configure the bit rate, I used the following sources:
https://www.port.de/en/bit-timing.html
https://www.nxp.com/docs/en/application-note/AN1798.pdf?origin_team=T2VVBR6FR

 

The project and the schematic of the transceiver board are attached. I am glad to provide any additional information, if necessary. I also appreciate any tips on working with similar CAN devices.

Many thanks.

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