P300H
P300 Series Modem Installation and Operating Handbook
Page 30
[Async ESC Feature] & Aux Data Channel
ESC/Aux Port
A single port provides the interface for optional high rate async ESC
(IBS/SMS or Closed Net plus ESC), or the INTELSAT low rate async
IBS ESC channel.
Electrical Interface
RS232, RS422, or RS485 external interfaces or internal link to Remote
M&C port (software selected). No external cabling required between
the ESC and M&C ports for M&C via ESC channel within overhead.
Other devices externally wired in parallel with M&C port can also be
accessed remotely.
Aux Data Channel
IBS
INTELSAT low rate async ESC definition carried in bit 1 of TS32
providing a synchronous channel at 1/480th of the data rate, allowing
up to one quarter of this rate for oversampled async data. Compliant
with INTELSAT IESS 403 low rate ESC definition.
[Async ESC Feature]
Closed Net plus ESC
Overhead scales to provide any user specified async ESC Baud rate
whatever the satellite data rate. ESC limit is approx 70% of main
channel rate, overhead varies from <0.5% to >70%
IBS/SMS
High rate async data using from 1/32nd to 22/32nd of the IBS
overhead, providing async baud rates from 0.2% to 5.1% of the
terrestrial rate (eg up to >2400 Baud at 64 kbps). Includes modes
compatible with the P400 Series, P230 & P1300/P1361 (using 20/32nd
of the overhead).
[IDR Option]
IDR ESC Audio Interface
Two 32 kbps ADPCM channels, 4 wire 600 , +7dBm to -16dBm
(software programmable in 0.1dB steps)
Backward Alarms
Outputs: Four `form C` relays
Inputs: Four protected inputs, short to 0 V to send alarm, with matching
summary Rx fail output. Alarm inputs software configurable for:
a) All external patch
b) 1=Rx fail & 2-4=External Patch
c) 1=Rx Fail & 2-4=OK
d) 1-4=Rx Fail.
ESC/Aux Ports
When the IDR option is fitted, independent ESC & Aux ports on the
IDR option replace the single shared ESC/Aux port of the base unit.
ESC Port
RS232, RS422, or RS485 external interfaces or internal link to Remote
M&C port (software selected). No external cabling required between
the ESC and M&C ports for M&C via ESC channel within overhead.
Other devices externally wired in parallel with M&C port can also be