The PCAN USB x 6 uses a green, 2-terminal Phoenix connector for the power supply input. These are available at www.digikey.com.
Phoenix mating connector: 2-pole, pitch 3,81 mm
Phoenix Contact MC1,5/2-STF-3.81 – PART No. 1827703
For use with GC-CAN-USB-6-DB9-FD / GC-CAN-USB-6-DB9-FD-ISO