Is Termination Resistor Needed With USB-8476S LIN Interface Device?

Updated Apr 18, 2024

Reported In

Hardware

  • USB-8476
  • USB-8476S

Driver

  • NI-CAN

Issue Details

I am using USB-8476S LIN Interface device.

Do I need to connect a termination resistance?
 

Solution

The LIN master node requires a 1 KΩ resistor and serial diode between the LIN bus and VBat.
On NI USB-LIN products, master termination is software selectable, thus you don't have to connect an external termination resistor to USB-8476S if you enable the Termination attribute .
This attribute can be enable using ncSetAttribute function within the NI-CAN Frame API.

If you are using LabVIEW, you should call ncSetAttr.vi to set Termination attribute to 1 as displayed below:

If you are programming in C, you should call ncSetAttribute to set Termination attribute to 1 in order to enable termination.
 

Additional Information

LIN cables require no termination, as nodes are terminated at the transceiver. Slave nodes are typically pulled up from the LIN bus to VBat with a 30 KΩ resistance and a serial diode. This termination is usually integrated into the transceiver package.

What is described in the Solution above also applies to USB-8476.
 

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