Installing HCD-E1 1
Quick Start Guide
Installation of HCD-E1 should be carried out only by an experienced
technician. If you are familiar with RAD's HDSL modems, use this guide to
prepare HCD-E1 for operation.

1. Installing HCD-E1

Switch and
Jumper Settings
HCD-E1 contains two sets of jumpers:
• Main board internal jumpers and DIP switch
• E1 sublink interface board jumpers.
If you are using HCD-E1 as a central unit (LTU), you can use the default
settings for the main board R/C jumper and DIP switch.
• If you are using HCD-E1 as a remote unit (NTU), do the following:
1. Turn the unit off.
2. Open the HCD-E1 case.
3. Set the R/C jumper (JP4) to the R (remote) position.
4. Set section 2 (DB INIT) of the S1 DIP switch to ON.
5. Turn the unit on for a short time (until self-test is completed).
6. Turn the unit off.
7. Set section 2 (DB INIT) of the S1 DIP switch to OFF.
8. Turn the unit on.
If you are operating HCD-E1 with a balanced E1 interface, you can use the
default settings of the sublink interface board jumpers.
• If you are using HCD-E1 with an unbalanced E1 interface, do the
following:
1. Turn the unit off.
2. Open the HCD-E1 case.
3. Identify and remove the three nuts that fasten the sublink interface
board to the spacers.
4. Remove the nuts and their washers.
5. Disconnect the flat cable from the connector J10 on the main board.
6. Hold the sublink interface board from its sides, and carefully pull it
straight up. Once the board is free, turn the board over the rear panel,
and let it rest on the work table. Do not strain the wires connecting
the board to the BNC connectors.