Specifications

External Channel Unit SDM-309B Satellite Modem
C-C–18 MN/U-SDM309B Rev. #
front edge of the card. The JP10 REM setting is used when loop timing is supported by
software on the M&C and will be included in the front panel menu.
Three fault outputs are provided on dry contact Form C relays. These are the COMMON
EQUIPMENT, MODULATOR, and DEMODULATOR faults. They are available on the
FAULT connector on the modem rear panel. Generation of these fault conditions is
described in Section 3.1.5. Fault indicators are also provided on TTL open collector
drivers on the V.35 connector. The TTL MOD fault indicates a MODULATOR fault or
COMMON EQUIPMENT fault, while the TTL DEMOD fault indicates a DEMOD or
COMMON EQUIPMENT fault.
Table C-3 lists the jumper settings for the V.35 interface. These jumpers are factory set
for a specific configuration. Clock selections, signal selections and loop timing can be
changed upon individual needs.
Table C-3 AS/0627-2 Rev E Board Jumper Selection
JP1 TX Clock Select Normal
Invert
Auto*
JP2 Interface Select V.35 (-2)*
JP3 RX Data Normal*
Buffer
JP8 RX Clock Normal*
Buffer
JP4 Address Set 1*
JP5 Address Set 0*
JP6 Address Set 1*
JP7 Address Set 1*
V.35 (-2)
JP9 CTS to RTS V.35* (Processor controller for V.35 &
RS232)
JP10 Loop Timing Auto
On
Off*
JP11 Asyn Clk Syn (-5) Cut Shorts
JP12 SCT 1 to 2 Invert
2 to 3 Normal*
JP13 RD 1 to 2 Invert
2 to 3 Normal*
JP14 RR 1 to 2 Invert
2 to 3 Normal*
JP15 DM 1 to 2 Invert
2 to 3 Normal*
JP16 SD 1 to 2 Invert
2 to 3 Normal*
*Indicates Factory jumper settings for V.35 interface type.