02-26-2014 04:11 PM
I have a CAN Breakout Box that was intended to simplify connecting multiple CAN nodes on a bus. I am currently using High Speed CAN cables with a total of five nodes (two ECUs, one Sniffer and two connected to a PXI chassis) at 250kbaud. I'm seeing lots of frame errors on the bus, only when the Breakout Box is connected, and it seems to be an issue with the termination resistance.
Generally I utilize a standard bus configuration wired using twisted pair cable with 120Ohm resistance on either end of the bus and stubs for each node. I'm wondering if the Breakout Box can be configured as a bus with termination resistance on both ends, similar to a standard bus. It seems that it's configured as a bus with only termination resitance on one end, so I'm wondering if this is the source of my error frames, and if I need to complete the bus by placing another external terminating resistor on the other end?
02-27-2014 06:33 PM
The wording in this KnowledgeBase article implies there is only one resistance in the break out box so I think you may be right. I would try adding an additional terminating resistor and see if that helps.