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Comtech EF Data SDM-309B User Manual

Page 225

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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.