# Connecting to station telephones

This topic provides information for connecting telephones to the CX 2000 board.

The CX 2000 board can connect to local telephones through up to 2000 feet of cable. Lines from local telephones to the CX 2000 board cannot run outside the building.

The station interface connector on the CX 2000 is a single MDR 68 pin connector on the end bracket (shown in the following illustration):

Connectors on a CX 2000 board

The CX 2000 board ships with one 3-foot cable (NMS P/N 32590) with an MDR 68 connector on one end and two RJ-21 connectors on the other. The stations are connected to the RJ-21 connectors using 66 or 110 blocks, as shown in the following illustration:

Connecting the CX 2000 board to stations

The following illustration shows the pin locations for each RJ-21 connector on the cable:

Pinouts for MDR-68 connector on CX 2000 board

The following table shows the pinouts for the MDR 68 connector:

Station | Ring pin | Tip pin |  | Station | Ring pin | Tip pin
--- | --- | --- | --- | --- | --- | ---
1 | 2 | 3 |  | 17 | 36 | 37
2 | 4 | 5 |  | 18 | 38 | 39
3 | 6 | 7 |  | 19 | 40 | 41
4 | 8 | 9 |  | 20 | 42 | 43
5 | 10 | 11 |  | 21 | 44 | 45
6 | 12 | 13 |  | 22 | 46 | 47
7 | 14 | 15 |  | 23 | 48 | 49
8 | 16 | 17 |  | 24 | 50 | 51
9 | 18 | 19 |  | 25 | 52 | 53
10 | 20 | 21 |  | 26 | 54 | 55
11 | 22 | 23 |  | 27 | 56 | 57
12 | 24 | 25 |  | 28 | 58 | 59
13 | 26 | 27 |  | 29 | 60 | 61
14 | 28 | 29 |  | 30 | 62 | 63
15 | 30 | 31 |  | 31 | 64 | 65
16 | 32 | 33 |  | 32 | 66 | 67

Note: Pins 1 and 68 are not used.

The following illustration shows the pin locations for each RJ-21 connector on the cable:

Cable (NMS P/N 32590) connector pinouts

The following table lists the pinouts for the first RJ-21 connector on the cable:

Station | Ring pin | Tip pin |  | Station | Ring pin | Tip pin
--- | --- | --- | --- | --- | --- | ---
1 | 1 | 26 |  | 13 | 13 | 38
2 | 2 | 27 |  | 14 | 14 | 39
3 | 3 | 28 |  | 15 | 15 | 40
4 | 4 | 29 |  | 16 | 16 | 41
5 | 5 | 30 |  | 17 | 17 | 42
6 | 6 | 31 |  | 18 | 18 | 43
7 | 7 | 32 |  | 19 | 19 | 44
8 | 8 | 33 |  | 20 | 20 | 45
9 | 9 | 34 |  | 21 | 21 | 46
10 | 10 | 35 |  | 22 | 22 | 47
11 | 11 | 36 |  | 23 | 23 | 48
12 | 12 | 37 |  | 24 | 24 | 49

Note: Pins 25 and 50 are not used on this connector.

The following table lists the pinouts for the second RJ-21 connector on the cable:

Station | Ring pin | Tip pin
--- | --- | ---
25 | 1 | 26
26 | 2 | 27
27 | 3 | 28
28 | 4 | 29
29 | 5 | 30
30 | 6 | 31
31 | 7 | 32
32 | 8 | 33

Note: Pins 9 - 25 and 34 - 50 are not used on this connector.

## Developer's cable kit

NMS provides an optional developer's cable kit (NMS P/N 80659). The kit contains two 10-foot RJ-21 cables and two breakout boxes. Each breakout box connects one RJ-21 to 24 standard RJ-11 (POTS) jacks for individual telephones. Use the cables to connect to the breakout boxes or to standard 66 or 110 blocks.

All components of the developer's cable kit sold by NMS are also commercially available from telephone product distributors such as Graybar and Anixter. These distributors can provide variations in cable lengths.