BACKPLANE

SECTION 23 BACKPLANE
23.1 DESCRIPTION

The 3000 Series Switch shelf backplane contains slots that modules are inserted into, to derive the module address. The backplane distributes:

•Power

•PCM paths

•Master clock

•Master sync

•Intra-Terminal data bus

•Channel status bus

•Control lines for data busses

The backplane has active circuitry that distributes PCM paths, master clock and master sync. The backplanes are connected together for complete distribution of receive and transmit signals to all shelves within the Switch.

23.2 BACKPLANE SETUP PROCEDURE

23.2.1 SHELF ADDRESS SETTINGS

Using the following table, determine the settings of Switch 1 for the Shelf Address of each shelf.

Table 23-1 SHELF ADDRESS SETTINGS
Shelf NumberSwitch 1, Open Sections

 

 

1

ALL Closed

2

1

3

2

4

1,2

5

3

6

1,3

7

2,3

8

1,2,3

9

4

10

1,4

11

2,4

12

1,2,4

13

3,4

14

1,3,4

15

2,3,4

16

1,2,3,4

17

5

18

1,5

23.2.2 TERMINATION SETTINGS

Using the following table, determine the switch settings for switches 2 through 8. All switches are

37.5ohms and normally set for 6 shelves.

• S2 - VTM PCM

• S3 - Primary Tx PCM

• S4 - Primary Rx PCM

• S5 - Master Sync

• S6 - Master Clock

• S7 - Secondary Rx PCM

• S8 - Secondary Tx PCM

Table 23-2 TERMINATION SETTINGS

Number of Shelves

Switch Sections

CLOSED

 

 

 

2

ALL

3

1,3,6,7,8

4

1

5

2,4,5,6,7,8

6

2,5,6,7,8

7

2,7

8

3,4,5,6,8

9

3,4,6,7

10

3,4,8

11

3,5,6

12

3,5

13

3,6,8

14

3,7

15

3

16

4,5,6,7,8

17

4,5,6,7

18

4,5,6

23.2.3 JUMPER DEFINITIONS AND SETTINGS

1.External Cable Connections

•J1/J2 - Shelf Interconnect

2.Primary Audio Connections

•J3/J5 - Primary Rx PCM

•J2/J4 - Primary Tx PCM

3.Secondary Audio Connections

•J23/J25 - Secondary Rx PCM

•J24/J26 - Secondary Tx PCM

23-1