Sevcon Gen4 CANbus (pdo/tpdo as digital input replacement)

[Adrianv544]

Hi all,

I've searched all over the internet to find an answer to this but cannot seem to. Preferably something I can confirm prior to attempting. Apologies if this is hidden somewhere in one of the many sevcon threads, I've spent so much time reading them I wouldn't be surprised if the answer went right over my head.

Any input from someone familiar with sevcons gen 4 controllers would be greatly appreciated.

Essentially I am trying to determine if I can map sevcon functions like FS1 / Deadman / drive profiles to a message broadcast over the CANbus rather than a digital input. Reason being is that we have a second controller for controlling the low voltage items such as indicators / lights / button inputs etc, but cannot pull the ~70V open pin voltage of the sevcon inputs with this controller without using relays. This is something I would like to avoid if possible.

I understand that the CANbus / PDO system can be used make the sevcon broadcast things like RPM etc over the CANbus, but I cannot, from what reading material I've managed to find, confirm with complete confidence that you can also configure inputs the same way. I am ~75% confident that I can, but cannot power on the sevcon and experiment until wiring is finished so was hoping I could determine the answer prior to that point so I can prepare by buying additional relays if I can.

Apologies for the wall of text and again, any input from anyone is much appreciated.

Thank you!!!

 

[Bernel]

In a word, yes you can receive the information of these switches over the CAN bus. Each of these switches need to be mapped, you can do that easily in the dvt software, then you have to add each switch to the tpdo. Each switch is one bit. I have mapped Forward, Reverse, FS1 and both Driveability selects. That is five bits, these five bits will all fall under one 8 bit value leaving three bits as zeros. You can than interpret the resulting binary or hex value to determine which bits have been enabled. I hope this makes sense.

Happy to help if you need more information.

Regards,

Bernel