CO-TB-RJ45 CANOpen Adapter


Purpose: provides a DS303-1 standard 5 Pin 5.08mm terminal block connector wired to two DS303-1 RJ45 connectors. Also provides optional connection to CAN_V+.

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I have standardized on RJ45 connectors for my CANOpen equipment. This adapter makes it possible to connect unusual equipment to RJ45 CANOpen networks by providing terminal block instead of a connector. I provide a connection for CAN_V+ in case it's needed.

Design Notes

The various signal lines are connected as follows:

  • CAN_H is connected to J2A (first RJ45 jack), J2B (second RJ45) and J1 (5-pin terminal block header)
  • CAN_L is connected to J2A, J2B, and J1
  • CAN_GND is connected to J2A, J2B, J1, and TB1 (power input terminal block)
  • CAN_SHIELD is connected to J2A, J2B, and J1
  • J2 reserved pins are connected: J2A pin 4 is connected to J2B pin 4 and J2A pin 5 is connected to J2B pin 5
  • TB1 CAN_V+ is always connected to J1 CAN_V+
  • TB1 CAN_V+ can be connected to J2A CAN_V+ and J2B CAN_V+ by using jumpers.

Normal Use

  • Connect the CANOpen wires from your device to the appropriate terminal. The pin out is below.
PinSignalPCB Name
  • Connect J2A and J2B to the rest of the CANOpen network using RJ45 cables
  • If the CANOpen device needs power on CAN_V+, you have many options:
    • Connect CAN_V+ power from TB1 to only this device: both jumpers are removed from JP1
    • Connect CAN_V+ power from TB1 to this device and all devices connected to the left RJ45 jack: only left JP1 jumper is installed
    • Connect CAN_V+ power from TB1 to this device and all devices connected to the right RJ45 jack: only right JP1 jumper is installed
    • Connect CAN_V+ power from TB1 to entire RJ45 network: both JP1 jumpers are installed
    • Break the link between CAN_V+ on the right RJ45 and the left RJ45: both jumpers are removed from JP1
  • So JP1 provides a lot of flexibility in providing multiple CAN_V+ voltages to your network -- but, as always, be careful, since you don't want to provide, say, +24VDC CAN_V+ to a device designed for +12VDC.

Bill of Material

PartVendorPart NumberQuantityDescription
PCBYour fab house 1
J1Phoenix ContactMSTBA 2,5/5-G-5,08 P/N 175727115-pin 5.08mm terminal block header
J2TE/AMP5557560-11Dual RJ45 Jack RA
JP1Molex10‑89‑70420->1Jumper block, 0.1", 2x2
TB1Phoenix ContactMSTBA 2,5/2-G-5,08 P/N 17572420->1Terminal Block Header, 2 pos, 5.08mm
Phoenix ContactFKC 2,5/5-ST-5,08 P/N 18730871Terminal Block Plug
Phoenix ContactFKC 2,5/2-ST-5,08 P/N 18730580->1Terminal Block Plug
Molex15-29-10250->2Jumper, 0.1""


  • Get the PCB made at your favorite PCB fab. Some will take Eagle files; almost all take Gerbers. I do not provide Gerbers because different PCB makers have different standards.
  • If you do not need to provide external CAN_V+, you can skip JP1,TB1, the terminal block plug, and the jumpers.
  • Terminal Block Plug: you can use any terminal block plugs that fits into the headers. I used spring clamp models (1873087 for J1 and 1873058 for TB1).
  • You can also used a fixed terminal block instead of the removable terminal block system I used for TB1. Some 5.08mm fixed screw terminal blocks have compatible PCB footprints.
  • Assembly should be easy - this PCB requires only standard through hole soldering techniques.
Last modified 6 years ago Last modified on Jun 20, 2013 10:49:30 PM