How to check if the CAN port is working?

[sys2eco-ha]

Hello, I am connecting a Stark CMR Module to a Deye 50 kW inverter and a BMW battery. The connection was successful, but I failed to manage the charging and the DC fuse blew. After replacing the fuse, I keep getting a message that there is no communication with the Deye inverter. There are no errors. I have several inverters, and it’s the same with another one. The battery is detected… How can I check if the CAN port is physically damaged? Thank you for your help.

[StarkJohan]

Good thing that you had proper fuses installed! With high bursts of energy there's unfortunately always risk of other hardware damage, even if fuses takes care of the real danger.

I can't speak for the inverter but I made a test for the CAN ports of the Stark CMR a little while ago. Use two wires to loop the CAN buses like the image shows, and run the test:

https://redispose.se/tests/

[sys2eco-ha]

Thank you for the quick response, we tried it but we are getting an error. We also changed the PC and the USB cables… what would be the next steps?

[sys2eco-ha]

esptool.js
Serial port WebSerial VendorID 0x1a86 ProductID 0x7523
Connecting...

Detecting chip type... ESP32
Chip Revision: 3
Chip is Unknown ESP32 (revision 3)
Features: Wi-Fi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
Crystal is 40MHz
MAC: 80:f3:da:f1:d0:c0
Uploading stub...
Running stub...
Stub running...
Changing baudrate to 921600
Changed
If the chip does not respond to any further commands, consider using a lower baud rate.
Flash ID: 174020
Connected! Flashing...
Warning: Image file at 0x1000 doesn't look like an image file, so not changing any flash settings.
Compressed 24960 bytes to 17831...
Writing at 0x1000... (50%)
Writing at 0x8c9d... (100%)
Wrote 24960 bytes (17831 compressed) at 0x1000 in 0.484 seconds.
Compressed 3072 bytes to 171...
Writing at 0x8000... (100%)
Wrote 3072 bytes (171 compressed) at 0x8000 in 0.039 seconds.
Compressed 1024768 bytes to 688572...
Writing at 0x10000... (2%)
Writing at 0x1d7fc... (4%)
Writing at 0x291dd... (6%)
Writing at 0x31719... (9%)
Writing at 0x4a721... (11%)
Writing at 0x514d0... (13%)
Writing at 0x5860f... (16%)
Writing at 0x5f9fa... (18%)
Writing at 0x671f7... (20%)
Writing at 0x6ebfe... (23%)
Writing at 0x75d10... (25%)
Writing at 0x7cd57... (27%)
Writing at 0x83d79... (30%)
Writing at 0x8ac24... (32%)
Writing at 0x91ded... (34%)
Writing at 0x98fb5... (37%)
Writing at 0x9fec4... (39%)
Writing at 0xa72b7... (41%)
Writing at 0xae288... (44%)
Writing at 0xb4cc5... (46%)
Writing at 0xbb7fe... (48%)
Writing at 0xc2a8f... (51%)
Writing at 0xc9c15... (53%)
Writing at 0xd10f5... (55%)
Writing at 0xd84e0... (58%)
Writing at 0xdfde0... (60%)
Writing at 0xe67a2... (62%)
Writing at 0xecdc0... (65%)
Writing at 0xf3ea7... (67%)
Writing at 0xfae39... (69%)
Writing at 0x10195d... (72%)
Writing at 0x1082ef... (74%)
Writing at 0x10ef41... (76%)
Writing at 0x1166be... (79%)
Writing at 0x11dbc5... (81%)
Error: Failed to write compressed data to flash after seq 34 failed with status 201,0