Product specifications

8–1
Chapter 8. CDI-40 ASI
INTERFACE MODULE
8.1 Introduction
The CDI-40 ASI Interface is a plug-in data module that inserts into the rear of the CDM-710
Broadcast Satellite Modem chassis. It provides physical and electrical connection between the
external terrestrial device and the internal circuitry of the modulator or demodulator.
By convention, a modem is Data Communications Equipment (DCE) where transmit data enters
the data interface and receive data exits it. The ASI plug-in interface has full duplex capability. In
addition, the module is automatically configured for simplex-transmit or simplex-receive
operation when the module is plugged into a simplex chassis configured for modulator only or
demodulator only operation.
Slot 1 of the CDM-710 – located at the center right of the chassis rear panel – is intended for the
dedicated placement of a CDI-40 ASI or CDI-60 HSSI Interface module. Slot 2 – located at the
right side end of the chassis rear panel – is assigned a blank panel or is restricted to the dedicated
placement of a CDI-70 10/100/1000 Base-T Gigabit Ethernet (GigE) Interface module, depending
upon configurations allowed at time of order.
8.2 Physical Description
The CDI-40 combines two electrical and physical interfaces into a single assembly. The ASI
section provides DVB compliant interface with BNC connectors. As shown in Figure 8-1, there
are two vers
ions of the CDI-40 ASI Interface module; block diagrams for both versions are
provided in Figure 8-2. Note the following:
ASI Interface Usage By Application
PL/10881-3 Standard non-redundant applications:
• Tx only 1:1 redundancy. Rx output (J2 and J3) is the standard ASI level
• Full duplex 1:N redundancy. Rx output (J2 and J3) is the standard ASI level
PL/10881-4 Standard non-redundant applications (excluding J3):
• Tx only, Rx only or full duplex (Tx and Rx) 1:1 redundancy (see Figure 8-3).
o Rx output J2 is standard ASI level
o Rx output J3 is higher so the standard level is delivered after a 3 dB combiner (see Figure 8-3).
• Full duplex 1:N redundancy (excluding J3).