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CAN protocol issue in OBD-II Emulator

Posted: Tue Mar 08, 2022 7:10 am
by przemhb
I am just taking my first steps with the OBD-II emulator. I am trying to use it with CAN protocol set. To test it I use STN1170 based OBD-II/BT interface and Maxhaust engine sound generator. Both use CAN protocol for communication. The STN1170 is a multi-protocol interface with CAN support, among dozen others. It works just fine in my car, and uses CAN to connect (verified).

For some reason both the Maxhaust and STN1170 interface are unable to communicate with the Freematics OBD-II Emulator. No matter CAN speed nor address length. If only I switch protocol to one of KWP2000's or ISO9141-2 everything works. Every PID is being read by Torque Android App.

What I am missing? Why CAN communication doesn't work for me?

Re: CAN protocol issue in OBD-II Emulator

Posted: Tue Mar 08, 2022 9:27 pm
by stanley
Our emulator does not actively generate CAN traffic. This is a bit different from real situation. It only responds to queries. That's the difference between emulator and simulator.

Re: CAN protocol issue in OBD-II Emulator

Posted: Wed Mar 09, 2022 8:47 pm
by przemhb
Thank you for your reply.
1. Why then it works in KWP2000 and ISO9141 modes?
2. Apps like Torque while connecting try to read basic information about the car, like VIN for example. So they send requests. After the connection is established they indeed merely listen to CAN traffic to read live data. Hence I'd expect Torque would be able to connect, but unable to refresh monitored PIDs. Am I right?

Re: CAN protocol issue in OBD-II Emulator

Posted: Thu Mar 10, 2022 8:47 pm
by stanley
ISO9141 is like serial communication. Sniffing or listening is not possible.