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Comtech EF Data SDM-100A User Manual

Page 131

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SDM-100A Satellite Modem

Theory of Operation

Rev. 0

4–15

17

P1

35

+TT

-TT

TT

J1

5

6

37,38

31,32

SD

+5V

-5V

+S

-SD

4

22

21

34
16

DEMOD FAULT

-MC

+MC

MC

DF

15

13

16

7

14

RS

CS

MF

MOD FAULT

+R

+C

+ST

25

27

3

23

5

8

26

+RT

-RT

-ST

+12V

RT

ST

33,34

10

8

11
12

35,36

RD
RR

-12V

+RD

-RD

24

6

31
13

29

+RR

+DM

-RR

GND

DM

GND

9

1,2
39,40

4

3

INTF1

INTF0

GND

1,19,20,37

-DM

11

Figure 4-6. RS-422 Block Diagram


Table 4-1. M&C Jumper Settings (AS/4973)

Jumper

Position

Function

JP10

1 to 2

RS-485

3 to 4

RS-485

5 to 6

RS-232-C

7 to 8

RS-232-C

JP22

3 to 4

RS-485

(also 1 to 2 = SDM-100 operation)

5 to 6

RS-232-C

JP2

1 to 2

4-wire

2 to 3

2-wire

JP3

1 to 2

4-wire

2 to 3

2-wire

JP11

1 to 2

CTS shorted to TX FPGA

3 to 4

CTS shorted to M&C

5 to 6

CTS shorted to RTS (RTS Loopback)

JP6, JP7 1 to 2

32/64k ROM size

2 to 3

128/256/512k ROM size


Notes:

1. JP6 selects ROM size for U207, XILINX firmware.
2. JP7 selects ROM size for U208, DSP firmware.