High-Speed CAN Pinout

Updated Jan 23, 2019

Reported In

Hardware

  • PXI-8461
  • USB-8473
  • PCI-8512
  • PCI-8513
  • USB-8502
  • PXI-8512
  • PXI-8513
  • PCI-CAN

Issue Details

I have a High-Speed CAN device. What is the pinout for this, and how does the DB-9 map to CAN signals?

 

Solution

High-Speed-CAN hardware have a 9-pin male D-SUB (DB9) connector for each port. The 9-pin D-SUB connector follows the pinout recommended by CiA DS 102.
 

CAN_H and CAN_L are signals lines that carry the data on the CAN network. These signals should be connected using twisted-pair cable. V– serves as the reference ground for CAN_H and CAN_L. V+ supplies bus power to the CAN physical layer if external power is required. All High-Speed Series 2 PCI, PXI, and USB hardware is powered internally, so it is not necessary to supply V+, unless you have configured the VBAT jumper for EXT. Shield is an optional connection when using a shielded CAN cable. Connecting the optional CAN shield may improve signal integrity in a noisy environment.

Additional Information

High-Speed CAN Cables should meet the physical medium requirements specified in ISO 11898, shown in the following table: 

 
The allowable cable length is affected by the characteristics of the cabling and the desired bit transmission rates. Detailed cable length recommendations can be found in the ISO 11898, CiA DS 102, and DeviceNet specifications. ISO 11898 specifies 40 m total cable length with a maximum stub length of 0.3 m for a bit rate of 1 Mb/s. The ISO 11898 specification says that significantly longer cable lengths may be allowed at lower bit rates, but each node should be analyzed for signal integrity problems.