# Keying the chassis

A CX 2000C board has several mechanical interlocks, called keys, that prevent the board from being inserted in a non-compatible chassis. Keying protects the board and other devices in the chassis from damage.

Before you install CX 2000C boards, configure the keying of your chassis to be compatible with the CX 2000C keying. This keying helps ensure that you do not accidentally insert an incompatible board in the chassis.

This topic describes how to key the slots in your chassis for CX 2000C boards. For detailed information on CompactPCI chassis keying, refer to the CompactPCI Computer Telephony Specification PICMG 2.5 R1.0 and to the IEEE 1101.10.

Warning: | To protect yourself and your equipment, allow only qualified personnel to install keying. The personnel must be familiar with the CompactPCI Computer Telephony Specification PICMG 2.5, R1.0 document. NMS is not responsible if you install a board into a chassis where keying has not been properly installed.

Note: A CX 2000C board will not function in a chassis that does not have a telephony backplane.

The following illustration shows how the CX 2000C board keys are configured:

The following illustration shows the keying chambers in a CompactPCI chassis that you must configure for a CX 2000C. You must also key rear panel keying chambers A through F that are not shown.

Chambers A, D, E, and F are defined by backplane wiring and network signaling levels. Chambers B and C are specific to the manufacturer.

Configure keying in the chassis as described in the following table:

Keying chambers on chassis | Configuration
--- | ---
A, B, and C (Front and rear) | Configure as shown in this illustration:
D, E, and F (Front and rear) | Configure as shown in this illustration:
J1 | Configure with a male brilliant blue key as shown:
J4 | Configure with a male strawberry red key as shown: