User's Manual

Table Of Contents

2. System Description 13

Power Supply Input

DC Input

-48 VDC

48v (Isolated Input); 2-pin captive power connector. The

Software Defined IDU™ requires an input of 48 volts dc

±10% at the rear panel DC Input connector. The total

required power is dependent on the option cards and

protection configuration (1+0, 1+1). The SDIDU

rear

panel power connector pin numbering is 1 through 2,

from left to right, when facing the unit rear panel. Pin 1

is the power supply return and is connected to unit

chassis ground internally. Pin 2 should be supplied with

a nominal 48 V dc, with respect to the unit chassis

(ground). A ground-isolated supply may be used,

provided it will tolerate grounding of its most positive

output.

The recommended power input is 44 to 52 V dc at 2

Amps minimum. It is recommended that any power

supply used be able to supply a minimum of 100 W to

the SDIDU

A mating power cable connector is supplied with the

Software Defined IDU™. It is a 2-pin plug, 5 mm pitch,

manufactured by Phoenix Contact, P/N 17 86 83 1

(connector type MSTB 2,5/2-STF). This connector has

screw clamp terminals that accommodate 24 AWG to 12

AWG wire. The power cable wire should be selected to

provide the appropriate current with minimal voltage

drop, based on the power supply voltage and length of

cable required. The recommended wire size for power

cables under 10 feet in length supplying 48 Vdc is 18

AWG.

The SDIDU

supplies the ODU with all required power

via the ODU/SDIDU

Interconnect cable. The Software

Defined IDU™ does not have a power on/off switch.

When DC power is connected to the SDIDU

, the digital

radio powers up and is operational. There can be up to

320 mW of RF power present at the antenna port

(external antenna version). The antenna should be

directed safely when power is applied.