P300H P300 Series Modem Installation and Operating Handbook Page 16
3 DESCRIPTION
3.1 OPERATION
The P300 Series modem are fully software controlled and with the exception of the optional G.703 interface
option there are no links or switches used to confi gure the unit. This enables all control and configuration
to be per form ed either locally from the front panel, or by remote M&C. Local control is by front panel
keyboard, and a large, easy to read, 80 character LCD display, with c lear, intuitive menus for configuration
and control. All the set-up parameters are stored in non-volatile memory which will retain data for a
minimum of 3 years, with no power applied. The receive and transmit functions of the Modem are
independent, so that they may be operated at a different data rates, IF frequencies, or different services if
required.
Like all Par ad ise Datacom products, the P300 Series includes a traffic log which stores the last 1000
events, suitably ti me-stamped. It can automatically add s ev eral measured para meters to the log a t operator
set intervals, including average & worst case Eb/No, average & worst case estimated user BER, average
& worst case estimated uncorrected BER, and the buffer fill state. The logged performance monitoring
allows investigation into cus tomer reports of poor link performance, and can provide a useful correlation
against weather conditions, et c.
3.2 FAULT PHILOSOPHY
Faults are split into two categories:
a) UNIT FAULTS: Equipment failures (such as a synthesiser lock failure).
b) TRAFFIC FAULTS: Data path failures, (such as a lack of input clock).
A full description of every detected fault, its category (unit or traffic), and the corresponding action taken
is provided in Appendix G - Fault Messages and Action Table. The response of the front panel LED
indicators and external fault relays res pond is described in the following sections.
3.3 ELECTRICAL DESCRIPTION
The P300 modem comprises of a single main modem Printed Circuit Board (PCB) with four optional
additional boards:
Optional G.703 interface (two different boards for T1 or E1 operati on).
Optional IDR ESC board which provides for all the IDR ESC requirements
Optional Monitor / AGC board which provides a user scalable AGC output and a constellation
monitor point.
Optional Turbo FEC daughtercard
For the P310, an L-Band daughterboard is also fitted internally above the main modem board, and further
three internal options are possible:
Reference oscillator options (several of vary ing stabilities)
An internal 100W PSU to provide a DC feed to an ex ternal BUC
An optional FSK communications board, to enable a modem and BUC to bo operated from the
modem front panel (and to provide closed loop power control to the BUC flange).