CANOpen + MicroBasic simultaneously?

The goal is to have an Arduino drive the Motor Control Unit (SBLM2360T) via CAN and I've selected CANOpen because "Practically all of the controller’s real-time queries and real-time commands that can be accessed via Serial/USB communication can also be accessed via CANopen". 

Test Setup:
* Solderless breadboard using the power lines to simulate a CAN bus, 100 Ohm resistors at each end
-- Shouldn't need them on something so short & didn't have 120 ohm in my supply cabinet
-- I do have 120 ohm resistors coming, but again, the "CAN bus" is only a few inches long, so they may not be needed at all according the my research.
* 2 @ Arduino w/ Seeed CAN-BUS Shield
-- One is the master, generating a CANOpen query for the motor amps
-- One is a CAN sniffer just reading traffic on the CAN bus
* MCU configured for CANOpen, ID #2 running a MicroBasic script that looks for CAN frames and prints them (script below)
* Everyone one is at 500 KBS, CAN Standard (11 bit frame)

The CAN sniffer can successfully see what the master is generating:
* Message ID: 0x602
* unsigned char stmp[8] = {0x44, 0x20, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00}; 

But I never see the MCU detect any CAN traffic. I've also got an oscilloscope connected to the bus configured to decode the traffic, but it isn't detecting the frames. So, I'm concerned that I don't have independent verification via the scope that the CAN bus is set up correctly other than the two Arduino's are exchanging information. 

Should I expect to be able to see CAN frames with a MicroBasic script while using CANOpen? The MCU *does* support CAN and USB simultaneously; correct? If that is correct, then is it reasonable to use the Roborun+ console to view CAN activity in the MCU?

I would greatly appreciate any thoughts on where I should look next for debugging. 

Thanks,

pdp

---

MicroBasic script:
`top:
`  if (getvalue(_CF, 1) > 0 ) then ' If one or more frame is received`
`   header = getvalue(_CAN, 1)`
`   byte_count = getvalue(_CAN, 2)`
`   byte_1 = getvalue(_CAN, 3)`
`   byte_2 = getvalue(_CAN, 4)`
`   print(header, "\t", byte_count, "\t", byte_1, "\t", byte_2, "\r")`
`  end if`
` wait(10)`
`goto top`

Thanks Athanisios,

Thanks for your response.

I apologize if I wasn't sufficiently clear; the goal is to use CANOpen because I am under the impression that I then do not need to write MicroBasic for motor control, but can concentrate all the logic in the Arduino code. That seems to be a more efficient development process. I'd like to be able to use the SDO 0x600 Command/Query to 0x580 Response cycle without any MicroBasic code although I may want to use TPDO message to broadcast basic motor stats and I understand one uses MicroBasic to write the stats to specific variables for transmission.

At this point, I am trying to use CANOpen with MicroBasic to confirm CANOpen messages are being received and recognized and was wondering if that was possible. Perhaps there are different CAN commands in MicroBasic for reading CANOpen or perhaps MicroBasic is ignored when CANOpen SDO's and PDO's are received. I'm just not clear on the relationship between the two.

Thanks,

pdp

Thank you so very much, this is very helpful!

Hi....CRC is utilized in CAN as it were so that a getting hub can choose whether to send an ack. In case there's no ack the message is re-transmitted until an ack is returned or until an blunder hail is set after different disappointments. Tragically, you can't tell whether the primary ack was sent by your aiming beneficiary or a few other hub. Subsequently my expansion of affirmation informing. I too do not think that the CRC field is passed into the get buffer, so my substance check is the less-comprehensive, but quick, information ^ complement in "void RECEIVE_MESSAGE ()".
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