8 asynchronous interface specifications – Comtech EF Data SDM-650B User Manual
Page 80

Configuration
SDM-650B Satellite Modem
3–38
Rev.
5
3.2.5.8 Asynchronous Interface Specifications
Main Channel
Physical Interface
MIL-STD-188-114.
(Factory Option)
RS-422/-449.
V.35.
G.703.
Data Rates
9.6K, 19.2K, 32 kbit/s to 8.448 Mbit/s.
G.703 Data Rates
1.544 Mbit/s.
(Jumper Selectable)
2.048 Mbit/s.
6.312 Mbit/s.
8.448 Mbit/s.
G.703 Line Code
AMI, B8ZS, B6ZS, HDB3.
Transmit Clock Reference
Internal modem reference or external transmit clock
(SCT or TT).
Jitter Attenuation
Per G.703.
Pulse Mask
Per G.703.
Overhead Channel
Overhead Rate
16/15 of main channel.
ASYNC Channel Rate (max.) < 1.875% of main channel.
ASYNC Channel Interface
RS-232-C.
2-wire RS-485 half-duplex.
4-wire RS-485 full-duplex.
Connector
25-pin D on breakout panel.
Baud Rates, Asynchronous
110, 150, 300, 600, 1200, 2400, 4800, 9600, 19200, 38400
bit/s.
Asynchronous Format
5, 6, 7, or 8 data bits.
Even, Odd, or No Parity.
1 or 2 stop bits (1 or 1.5 for 5 bit).
Buffer Specifications (Pleisiochronous/Buffer Operation)
Buffer Size
384 to 262144 bits, in 16-bit steps.
Buffer Fill Status
Monitored accurate to
± 1%.
Buffer Centering
Automatic or Manual.
Buffer Clock Reference
Transmit.
Internal (10
-5
Stability).
External.
Receive (Buffer Bypass).
External Clock Amplitude
Differential 0.5 to 5 Vp-p.
Unbalanced Mode 0 to 5 VDC.
External Clock Frequency
256 to 2048 kHz, in 64 kHz steps.
External Clock Impedance
100
Ω.
External Clock Input Type
Sine or Square wave.
50%,
± 10%.