User Manual

AS4000 Release3 and Release 4 Central

Terminal Installation and Commissioning

DLP-006

605-0000-432

Issue 1.3a Date 18th October 1999

Page 3 of 4

2. 2Mbit/s Cabling 120Ω Twisted Pair

From the site survey, confirm the location of the Digital Distribution Frame (DDF).

The length of 2Mbit/s feeds from the rack to the DDF should not exceed 250 metres

Note: This must be a SELV port of an EN 60950 approved product.

Run the 2Mbit/s twisted pair cables from the modem shelf to the allocated positions on

the DDF. (Two cables per shelf if using screen twisted pair or one cable if using

screened four wire). In partial equipped installations it may be appropriate to run

enough cables to cater for a complete rack of equipment. Identify and label each cable

at both ends as well as the DDF positions.

Feed the cables through the top and down the front of the rack. Tie in cables as

necessary using suitable cable ties, trim, leaving no sharp edges.

Feed the cable through the hole on the side of the modem shelf to access the

backplane.

Fit Ferrites to each cable at the point of entry to the shelf. Secure a tie wrap each side

of the ferrite to keep it in place.

Terminate cables on 9 Way D-Type 2Mbit/s Out 6 & 7, 2Mbit/s In 2 & 3, Screen on 5

& 9. See Figure 20

9 Way Male (120

ohm)

2Mbit/s In

2Mbit/s Out

Screen

Screen if two cables

Figure 20. 120 balanced connections

For 120Ω balanced operation JP5, JP6 and JP7 should be removed. See Figure 21.

Fit the D-type connector to P1 on the Modem Shelf Backplane See Figure 21.