3020-dda.ib.rev0.doc
Page 5 of 17
09/03/2006
Technical Specifications
IRT Eurocard module
Type DDA-3020
In accord with ITU-T Rec. G.703 155,520 kb/s –
see
Electrical characteristics of G.703 signals
.
Input:
Type Transformer
coupled.
Impedance 75
Ω
terminated.
Equalisation
Automatic for up to 200 m of Belden 8281 equivalent.
Outputs:
Number
1 switched, 3 non-switched, regenerated, reclocked unshaped outputs
located on rear connection assembly and 1 located on front panel.
Impedance 75
Ω
source terminated.
Electrical Characteristics:
Cable Type
Coaxial
Impedance 75
Ω
Signal level
1.0 V
Pulse Shape
Unshaped, fig. 22&23/G.703
Nominal pulse width
9.64 ns
Code conversion
Code Mark Inversion (CMI)
Return loss at input ports
> 15dB over frequency range 8 MHz to 240 MHz
Controls & alarms:
Input:
External changeover request
A ground applied to this input will emulate the operation of the front panel switch
“Change Request”.
Outputs:
Power Failure
Contact closure to ground if power has failed.
General alarm
Contact closure to ground if
a. Data Loss is detected OR
b. AIS is detected AND the AIS disable link (LK 3) is not installed.
AIS detection is defined as a series of all “1”s in the payload of a frame.
Data Loss is defined as less than 120 data “1”s in 512 G.703 data rate clock
periods.
Connectors:
Data: BNC
Alarm:
Krone LSA plus
Indicators:
DC power.
Data
loss.
AIS
detect.
Module in service.
Module in standby.
Power requirements
28 Vac CT (14-0-14) or
±
16 Vdc.
Power consumption
< 4 VA
Temperature range
0 - 50° C ambient
Mechanical
Suitable for mounting in IRT 19" rack chassis types with input output and power
connections on the rear panel.
Finish:
Front panel:
Grey, silk-screened black lettering & red IRT logo.
Rear assembly:
Detachable silk-screened PCB with direct mount connectors to Eurocard and
external signals.
Dimensions
6 HP x 3 U x 220 mm IRT Eurocard
Standard accessories
Rear connector assembly.
Optional accessories
ZDA-3021RH double width rear assembly.
Due to our policy of continuing development, these specifications are subject to change without notice.
IRT
Communications
www.irtcommunications.com
