CAN BUS PXI 8461 over RS-485

Dear Ladies and Gentlemen,
in one of our projects we are trying to use a CAN Bus system over RS-485. I have got doubts if this can be realized since RS-485 is different to CAN Bus. RS-485 does not support any multimaster configurations without bigger efforts and so on. But this is not the issue for my question here. On a prototype board I implemented RS-485 drivers and receivers. I am trying to find a circuitry to run CAN bus via RS-485. The test setup shall be quite easy. PXI 8461 card -> RS-485 -> ASIC (with the implemented CAN Bus system) and the same way back. It is just a point to point connection. No multimaster configurations will be tested. My question is now if it is possible to use the PXI 8461 card in general? I am not sure if the electrical levels are equal. Perhabs somebody used this card in my configuration and can give me some support. If it is not possible are there any recommendations which cards can support my configuration?
Thanks a lot for your help!
Best regards,
Ingo

Hello Ingo,
thank you for contacting National Instruments. RS-485 specifies an electrical standard, like differential signal transmission and with a voltage around +/-200 mV. A DC-Offset from -7 to +12 Volts is allowed.
The CAN-Standard uses Voltages from -27 to 40 Volts. As you can see, you can not switch the electrical specification from CAN to RS-485, because the voltages differ already to much.
Why do you have the need to reduce the CAN Voltage down to RS-485 levels?
Best regards
MarianO

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