Comtech EF Data SDM-2020 - Manual (Page 163)

SDM-2020 Satellite Modulator Revision 7
ASI/LVDS Data Interfaces MN/SDM2020M.IOM
13-7
13.1.4.1 L
OOPBACK
C
ONNECTION
Refer to Table 13-3 for additional requirements for Loopback .
Table 13-3. Loopback Connections
ASI Interface is active
in Modulator Loops ASI input, J3 (or J4), to ASI output, J7. If JP1 is Off, then J3 (J4)
also loops to J6, the LVDS-DVB parallel output
The LVDS signal contains D0-D7, Sync, Dvalid, and Clock
LVDS Interface is
active in Modulator If J1 is On, then J6 (LVDS-DVB input) is looped to the ASI output J7.
ASI Interface is active
in Demodulator JP1 is Off (Normal): When Loopback is engaged the TX ASI (J3) input
connects simultaneously to the RX ASI (J7) and to the RX LVDS
connector (J6). The LVDS signal contains D0-D7, Sync, Dvalid, and Clock
JP1 is On: When Loopback is engaged the TX LVDS (J6) input connects
to the RX ASI (J7) connector.
LVDS Interface is
active (output) in
Demodulator JP1 is ON: When Loopback is engaged the TX LVDS (J6) input connects
to the RX ASI connector (J7). The LVDS signal contains D0-D7, Sync,
Dvalid, and Clock.
JP1 is OFF (Normal): When Loopback is engaged the TX ASI input
connects to the RX ASI connector and to the RX LVDS connector. The
LVDS signal contains D0-D7, Sync, Dvalid, and Clock.
13.1.4.2 L
OOP
T
HROUGH
The operation of Loop Thru is the same as Loopback except the normal operating mode
not a test mode, and the TEST LED does not illuminate
.
13.1.5 ASI C
ONNECTOR
P
INOUT
J3, J4 Transmit Data Input, BNC female
J7 Receive Data Output, BNC female