Comtech EF Data SDM-2020 - Manual (Page 180)

SDM-2020 Satellite Demodulator Revision 4
G.703 Data Interface MN/SDM2020D.IOM
11–14
11.1.8 Terrestrial Interface Types
11.1.8.1 Send Data (SD), Receive Data (RD), and External Clock
Connectors J3, J4 & J6
The Send Data (SD) (J3), Receive Data (RD) (J4) and Ext. Clock (J6) connectors are all
BNC type connectors, and are terminated into 75
Ω.
11.1.8.2 Auxiliary Functions Connector, J5
This port provides for other modem-specific signals not otherwise defined for either or
both of the two data connectors. (Refer to Table 11-11).
The connector is a 9-pin sub-miniature D female, with threaded jack nuts.
Demodulator Fault (DF) is a single ended open collector signal, where:
Voh=12V max. and Vol=0.5V max. @ Iol=8 ma.
A pull-up resistor external to the equipment is required.
A (DF) fault is indicated by an OFF (Vout = Hi) open collector transistor and the normal
OK state is indicated by an ON transistor (Vout = Lo).
The Carrier Detect (CD) signal is a TTL output. When CD is high, it indicates the
demodulator is locked.