Comtech EF Data SDM-650B - Manual (Page 75)

SDM-650B Satellite Modem Configuration
Rev. 5 3–33
The “handshake” asynchronous signals are:
• RTS
• CTS
• DM
• DSR
• RR
• RLSD
This board may otherwise contain the circuitry for transformer balanced data interfaces
supporting CCITT G.703 parameters. Data inputs are SD, and outputs are RD. Data rates
of 1.544, 2.048, 6.312, and 8.448 Mbit/s are supported.
Note: 6 and 8 Mbit/s are not supported by the modem.
Line codes for zero substitution are B6ZS, B8ZS, and HDB3. AMI is also supported. The
configuration of this section is determined during production and is not user selectable in
the field.
The asynchronous data channel has three interface options. The RS-232-C electrical
interface allows full-duplex operation. The RS-485 4-wire option also allows full-duplex,
and RS-485 2-wire allows half-duplex operation. These options are jumper selectable.
Tables 3-6 and 3-7 describe the configuration of the jumpers for the various options and
data rates. Figure 3-13 shows the jumper locations.
JP4 1
1 2
JP11
AS/1311 REV___
JP5
1
JP6 JP7
JP8
1
JP13
1
1 1
1 1
JP12 JP9
JP3
2
1
ASYNC OVERHEAD TERRESTRIAL INTERFACE BOARD
JP1 JP2
1 2 1
JP10
1
JP11
1
Figure 3-13. Asynchronous Overhead Jumpers