The distance between the transceiver inputs and the cable trunk, which is known as the stub, must be short as possible when connecting a node to the bus. Stubs present a non-terminated piece of bus line which can introduce reflections as the length of the stub increases. As a general guideline, the electrical length, or round-trip delay of a stub, must be less than one-tenth of the rise time of the driver, thus giving a maximum physical stub length as shown in Equation 1.

where:

• t_r is the 10/90 rise time of the driver
• c is the speed of light (3 × 10⁸ m/s)
• v is the signal velocity of the cable or trace as a factor of c