Premier Mounts CDM-600 Rx and Tx if Connectors J1 and J2, Overhead Data Connector P3A

CDM-600 Satellite Modem	Revision 7
Physical Description	MN/CDM600.IOM

4.3.2Rx and Tx IF Connectors (J1 and J2)

The IF port connectors are both a 50Ω BNC female type. 75Ω cable connectors (male) will have no problem mating with this 50Ω type. The electrical impedance presented by these connectors is controlled internally by an RF-switching arrangement. This selection between 50Ω and 75Ω is controlled either via the front panel menus, or via the remote control bus.

4.3.3Overhead Data Connector (P3A)

The Overhead data connector is a 25-pin ‘D’ type male (DB25-M). It is used for passing components of INTELSAT specified overhead frame structures. These include 64 kbps EIA-422 and 1/16 IBS overhead ESC at EIA-232. The IDR backward alarm inputs are found on this connector.

4.3.4Data Interface Connector (P3B)

The Data connector is a 25-pin ‘D’ type female (DB25-F). This connector conforms to the EIA-530 pinout, which allows for connection of different electrical standards, including EIA-422, V.35, and EIA232. A shielded 25-pin ‘D’ type provides a very solid solution to EMC problems, unlike the sometimes used V.35 Winchester connector.

It is the responsibility of the user to provide the appropriate cables to connect to this EIA-530 connector.

IMPORTANT

4.3.5External Reference Connector (J9)

This is a BNC female connector. It is used for operating the buffer with an external station reference. It requires an EIA-422 compatible level, so this unbalanced input should have a zero volt offset and a swing of at least ± 2V into the 120 Ω termination provided.

4.3.6Audio Connector (P4A)

The Audio connector is a 9-pin ‘D’ type female (DB9-F). It is used for the two 32 kbps ADPCM audio inputs and outputs (600 Ω transformer coupled, balanced signals). These can be used for both ESC voice circuits in IDR mode, or as the primary data (FAST option).

4–3