# System requirements

To install and use CX 2000C boards, your system must have:

- Natural Access installed.

- An uninterruptable power supply (UPS). Although a UPS is not strictly required, it is strongly recommended for increased system reliability. The UPS does not need to power the PC video monitor except in areas prone to severe lightning storms.

- A CompactPCI chassis with an H.110 compliant telephony backplane with an available CompactPCI bus slot. For more information about chassis, refer to Selecting a CompactPCI chassis.

Note: The CX 2000C board will power up and function only in a chassis with a telephony backplane.

- A protective earth connection (required by UL and CSA safety approval). A grounded lug must be provided on the chassis. The lug must be connected to a permanent ground such as a metal water pipe.

- A power supply. For more information, refer to Using the NMS rack mount power supply chassis or Using an alternative power supply.

Caution: | Each CX board is shipped in a protective anti-static container. Leave the board in its original container until you are ready to install it. Handle the board carefully and hold it only by its handles. We recommend that you wear an anti-static wrist strap connected to a good earth ground whenever you handle the board.

## Selecting a CompactPCI chassis

Use the following guidelines when choosing a CompactPCI chassis:

- The chassis must have high enough air flow to cool the CX 2000C. If the chassis manufacturer specifies air flow, the air flow rating must provide at least 200 linear feet per minute per slot of room temperature air.

If an air flow rating is not specified, use one fan with a rating of at least 50 cubic feet per minute (CFM) for every four CX 2000C boards. There should be no preheating of the air before cooling the CX 2000C board.

- The chassis must have provisions for a protective grounding lug to maintain UL, CSA, and EN 60950 certifications.

- The chassis must have a telephony backplane with H.110 bus support.

- Ideally, the chassis contains busses to distribute power from the ringing power supply to the boards. Busses reduce the amount of cabling required. Six distribution busses across the backplane are needed, rated as shown in this table:

Chassis connection | Chassis backplane current per board
--- | ---
-V bat | 1A
V bat Rtn | 1A
SELVbat | 1A
SELVbatRtn | 1A
VRG | .250A
VRGRtn | .250A

NMS supplies a cable to connect a power supply to a chassis with a telecom power bus. One end of the cable has spade lugs to connect to the chassis. To learn more about connecting power in this way, refer to Using the NMS rack mount power supply chassis.

- If you install an uninterrupted power supply and use it to back up the NMS rack mount power supply (described in Using the NMS rack mount power supply chassis), it should be rated for at least 1.8 kW.

- Hot Swap support is recommended as a chassis and host CPU feature.

- To allow insertion of the rear I/O transition board, the chassis must have the rear I/O connector alignment feature. Some older CompactPCI chassis do not have this feature. Contact the chassis manufacturer to find out if your chassis supports this rear alignment feature.

- Early CompactPCI chassis without alignment pins are not supported.

- To support the 48 port, PBX version of the CX 2000C board, the chassis must have a 500 Vdc breakdown between the pins on J3 listed in the following table, and all other signals (most importantly the +5 and ground layers). This is necessary to maintain safety approvals and to support ringing signals.

The following table shows the pins requiring clearance for J3/P3:

Pos# | RowZ | RowA | RowB | RowC | RowD | RowE | RowF
--- | --- | --- | --- | --- | --- | --- | ---
19 |  |  |  |  |  |  |
18 |  |  | T33 |  |  |  |
17 |  |  | R33 | T39 | T44 |  |
16 |  |  | T34 | R39 | R44 |  |
15 |  |  | R34 | T40 | T45 |  |
14 |  |  | T35 | R40 | R45 |  |
13 |  |  | R35 | T41 | T46 |  |
12 |  |  | T36 | R41 | R46 |  |
11 |  |  | R36 | T42 | T47 |  |
10 |  |  | T37 | R42 | R47 |  |
9 |  |  | R37 | T43 | T48 |  |
8 |  |  | T38 | R43 | R48 |  |
7 |  |  | R38 |  |  |  |
6 |  |  |  |  |  |  |
5 |  |  |  |  |  |  |
4 |  |  |  |  | RING2 |  |
3 |  |  |  |  |  |  |
2 |  |  |  |  |  |  |
1 |  |  |  |  |  |  |