Nortel Networks DCT1900 - Manual (Page 209)

Technical Product Manual - DCT1900
Installation Instructions, Digital Trunk Unit (DTU-T1, CAS) - REX-BRD0021 or 2/ROFNB 157 13/2
Install-DCT1900/R8/mw 12-1
© 2000-2005
C HAPTER 12
Digital Trunk Unit (DTU-T1, CAS) - REX-BRD0021 or 2/ROFNB 157 13/2
12.1 General
The DTU–T1 provides 48 communication channels with the PBX via two 1.544Mbit/s links.
Maintenance
The DTU–T1 has the following field–exchangeable parts (see Figure 12-1 for placement &
orientation):
z DTU–T1 CAS Firmware RYS 105 660 (Factory Installed)
12.2 Board Description
The DTU–T1 Board contains two identical Digital Trunk Circuits (DTC1 and DTC2), each with their
own identical connectors and LEDs.
Jumpers
The line length selection can be adjusted with the three jumpers, 1, 2, and 3 (see Table 13-1).
Cables
The DTU-T1 interfaces via 100 ohm twisted pair cable only (AWS1034)
Connectors
The DTU–T1 board has two connectors on the front, one for each DTC. The connectors are for
twisted pair connections to the PBX.
LEDs
Each DTC has its own LEDs:
LED1
Green : Normally on. Power On LED
LED2 Red : Normally off. Watch–dog LED
LED3 Red : Normally off. Board not polled LED
LED4 Red : Normally off. Board Error LED
12.3 Installation
1. Place the DTU–T1 Firmware PROMs and set the jumpers (see Figure 12-1 and Table 12-1).
2. Insert the DTU–T1 on to the card guide in the specified board position.
3. Gently push the board into the backplane connector until it locks. Don’t use any force.
4. Connect the cable, AWS1034, to the front of the board.