Comtech EF Data SDM-300A - Manual (Page 346)

SDM-300A Satellite Modem Revision 6
Troubleshooting MN/SDM300A.IOM
18–10
Table 18-2. SDM-300A Fault Tree (Continued)
TX I
F OUTPUT OFF
TX FAULT LED TX FAULT RELAY RX FAULT LED RX FAULT RELAY COM EQ FAULT LED COM EQ FAULT RELAY TX ALARM LED TX ALARM RELAY #2 RX ALARM LED RX ALARM RELAY #3 SPARE RELAY AL
ARM #1
PRIMARY ALARM RELAY SECONDARY ALA
R
M RELAY
IBS BACKWARD ALARM DEFFERED MAIN ALARM TX AI
S
RX AIS D&I TERR BWA
TX INTERFACE FAULTS
(1) (2) (3) (4) (5)
(6)
**
*** (7)
**
***
**
***
(8)
*
*
**
***
*
**
***
***
TX DROP X X X X X
TX DATA/AIS X X X X X
TX CLK PLL X X X X X
TX CLK ACTIVITY X X X X X
TX AUDIO 1 CLIP X X
TX AUDIO 2 CLIP X X
RX INTERFACE FAULTS
BUFFER UNDERFLOW X X
BUFFER OVERFLOW X X
RX DATA/AIS X X X X X X
FRAME BER X X X X X
BACKWARD ALARM X X X X
BUFFER CLK PLL X X X X
BUFFER CLK ACT X X X
DEMUX LOCK X X X X X
RX 2047 LOCK X X
BUFFER FULL X X
RX INSERT X X X X
RX AUDIO 1 CLIP X X X
RX AUDIO 2 CLIP X X X
Legend
Test Note Fault/Alarm Relay Test Points Connector/Pins
(1) TX FAULT Pin 4 (NO), 5 (COM), 6 (NC) ****
(2) RX FAULT Pin 7 (NO), 8 (COM), 9 (NC) ****
(3) COM EQ FAULT Pin 1 (NO), 2 (COM), 3 (NC) ****
(4) TX ALARM #2 Pin 4 (NO), 5 (COM), 6 (NC) ****
(5) RX ALARM #3 Pin 7 (NO), 8 (COM), 9 (NC) ****
(6) PRIMARY ALARM Pin 43 (NO), 10 (COM), 27 (NC) ****
(7) SECONDARY ALARM Pin 44 (NO), 11 (COM), 28 (NC) ****
(8) DEF MAINT ALARM Pin 17 *****
* IDR only.
** IBS only.
*** D&I only.
**** A connection between the common and N.O. contacts indicate no fault/alarm.
***** Signal is open collector high impedance if faulted.