Termination
This section applies to S/T interface users in Australia and North America, and provides instructions to help set up termination scenarios. Termination requirements vary according to: the number of devices connected to the NT1; and the distance between the devices and the NT1.
For users who require termination, the Eiconcard C21 S/T has been shipped with a separate terminating resistor. For information on how to install the terminating resistor, see “Installing a Terminating Resistor” on page 12.
How do I determine the termination value?
Single ISDN Device
If the NT1 is connected to a single ISDN device (e.g. Eiconcard C21), follow the instructions below.
75 meters or more
If the connection spans 75 meters (250 feet) or more, connect the 100 ohm terminating resistor included with the ISDN cable. Set the NT1 to provide 100 ohms of resistance. Consult the manual provided with the external NT1 for more detailed instructions.
Note Some NT1s do not support connections over 75 meters (250 feet). Check your user documentation to determine the distance supported.
75 meters or less
If the connection spans less than 75 meters (250 feet), set the NT1 to 50 ohms of resistance, and do not connect the terminating resistor. Consult the manual provided with the external NT1 for more detailed instructions.
Termination11
