SkyWave IDP-680, Hardware Manual

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IDP 600 Terminal Series - Hardware Guide
© SkyWave Proprietary 17 T200, Version 02
3.4 Serial Interfaces
3.4.1 RS-232
The RS-232 interface defaults to the following settings: 9600 bit/s, 1 start, 8 data, 1 stop
bit, no parity. The baud rate is configurable up to 230,400 bit/s.
The electrical characteristics of the interface are:
Parameter Minimum Typical Maximum Units
Serial Rx Input Low Threshold 0.6 - - V
Serial Rx Input High Threshold - - 2.4 V
Serial Tx Low Output
(3 K load) - - 3.7 V
Serial Tx High Output
(3 K load) 3.7 - - V
3.4.2 RS-485/J1708
The terminal can be configured for an RS-485 or J1708 interface. It can be used for
general bus or for SCADA interfacing. The RS-485/J1708 does not incorporate a
termination resistor.
The electrical characteristics of the interface are:
Parameter Minimum Typical Maximum Units
Input Common Mode Voltage -7.0 - +12 V
Differential Input Threshold -200 -125 -50 mV
Output Common Mode Voltage - 1.5 3.0 V
Differential Drive Output, 54 Ω load 1.5 - - V
3.5 RF Specifications
3.5.1 Frequency
Parameter Value
Receive
Frequency Band 1525 to 1559 MHz
Modulation OQPSK
Symbol Rate 3000 symbols/seconds
Polarization RHCP
Transmit
Frequency Band 1626.5 to 1660.5 MHz
Modulation OQPSK
Symbol Rate 900 symbols/seconds (maximum)
Polarization RHCP