Using Object Buffers in a USBcan Light 2xHS

13/09/2019 by Kvaser

The answer is No to using Object Buffers in a USBcan Light 2xHS:

  1. The USBcan Light 2xHS does not support Object Buffers.
  2. An Object buffer can only contain a single message to be transmitted. So, to perform SRDO you would need to setup two periodic Object buffers and then have no control over the synchronicity between the two buffers. To achieve SRDO, this is not a desirable design.

I believe a USBcan Pro v2 unit using t programs could handle SRDO processing locally. The SRVT is specified in milliseconds (the maximum gap between the two periodic transmissions (normal and inverted)). Since the t program scheduler runs at 1 ms and handles every timer event and one message event, as long as the SRVT is 2 ms or greater, they will probably not see an issue. At an SRVT of 1 ms, they may see some issues depending on how the receiving nodes timers are aligning with the scheduler timing (ie. race conditions).

Here is a link to where you can download the SRDO description:

https://www.systec-electronic.com/en/products-technologies/cancanopen/add-ons/canopen-cia-304-srdo-add-on/