Each Gateway facilitates providing one half of the termination required for a CAN bus to operate correctly. Below are instructions for how to enable the termination and the working principles for split termination. # Enabling Bus Termination Located on the back of the device is a slot containing a switch which when moved to the "on" position enables the termination resistor network. Note: When the switch is in the "on" position, termination is provided even if the Gateway is powered off. # About Split Termination Split termination provides a superior method of bus termination by creating an equivalent low-pass filter for both High and Low CAN bus lines. The below diagram shows the difference between standard termination and split termination:  ## Operating Principle The split termination topology can be considered as two RC low-pass filters with a common capacitor. As such, the standard RC filter equation can be used: $ f_c = {1 \above{1pt} 2 π R_{term/2} C_L} $ Substituting in the values of the termination present in the Gateway we get: $ f_c = {1 \above{1pt} 2 π \cdot 30.2 \cdot 4.7 \cdot 10^{-9}} = 1.121 \space MHz $ While the corner frequency may fall below some of the operational data rates on the bus, this is acceptable as the circuit doesn't impose a DC load on the differential bus signal and only effects common mode noise. # References - [Why Are Termination Networks in CAN Transceivers So Important? - Texas Instruments](https://www.ti.com/lit/ta/ssztb40/ssztb40.pdf) - [Timing 101: The Case of the Split Termination - Silicon Labs](https://community.silabs.com/s/share/a5U1M000000ko0gUAA/timing-101-the-case-of-the-split-termination?language=es)