DMC60C CAN communications

[Jani]

Hi!

Nice to see you got CAN version already!

We would like to use our existing CAN network to control big DC motors, such as fans and linear motors. This controller would be perfect. We would have four of these connected to same CAN bus.

Problem is that there is no CAN communication documentation yet, and we are not using any robot controllers.

What protocol is this using? CANopen?

What i want to do:

1.set some node ID for the controller , so i can control these motors individually.

2. Set pulsewidth from -100% to +100%

3. Get heartbeat from the controller so i know it's alive

All i need is some CAN IDs, and info on what bytes control what

Thanks!

Jani

 

[JColvin]

Hi @Jani,

I do not know for certain what protocol the DMC60C is using (I will find out), but we do have documentation for the API that the DMC60C uses available here: https://reference.digilentinc.com/dmc60c/api/index.html. Otherwise, the Resource Center for the DMC60C has some additional information including a Getting Started Guide that you may find useful as well.

Let me know if you have any other questions.

Thanks,
JColvin

[adamkolesar]

I am also interested in the questions Jani asked.

Is there any documentation yet?

[JColvin]

Hi @adamkolesar,

I recommend taking a look at this page as it contains all of the documentation for the DMC60C API; the specific page for the WPI functions can be found here.

Let me know if you have any questions.

Thanks,
JColvin

[clintr-at-kornak]

Hello, I'm hoping one of you might be able to answer some questions about getting CAN communications working?

I'm trying to communicate between a DMC60C and an MCBSTM32 dev board.  Here are some details of my setup:

The dev board includes a 120 ohm termination resistor on the CAN bus.
From the DMC60C, I have connected one of the signal cables to my dev board, and I've put a 120 ohm termination resistor across the other signal cable.
I don't know what data rate the DMC60C expects on the CAN bus, so I'm using 500kbps for now.
I'm using the DMC60C CAN Protocol Guide (October 24, 2018), as a reference.
I power up the DMC60C, wait for the LEDs to stop showing blue and start alternately flashing red-on-top/red-on-bottom, then have my dev board send the msgIdEnum message.  I can see on a 'scope that the data is sent correctly, but the DMC60C doesn't assert the ACK bit at the end of the message.

Here are the questions I have.

1. What is the expected CAN data rate?
2. Could you please confirm these details for the msgIdEnum message:
 - sent with the 29-bit message identifier == 0x00000240
 - no data bytes
3. The signal cables each have a green wire and a yellow wire; which is CAN-High and which is CAN-Low?  (I have tried both ways.)
4. The voltage difference on the CAN bus is about 2V when transmitting a zero bit - does it need to be higher?

Thanks, any help is appreciated.
 

[clintr-at-kornak]

Got it working using the setup I described, but with 1000 kbps data rate, yellow=CAN-High, green=CAN-Low.