SP503AN

SP503 Application Note

© Copyright 2000 Sipex Corporation

3

DTE-DCE flexibility with the SP503 on a DB-25 serial port

DB-25

Connector

TxD

TxC

DTR

RTS

RxD

RxC

CTS

DCD

TxD

TxC

DTR

RTS

RxD

RxC

CTS

DCD

RDEC0

RDEC1

RDEC2

RDEC3

TDEC0

TDEC1

TDEC2

TDEC3

2 3

4

5 12 11 10 9

2345 12 11 10 9

14

15

13

16

1

20

80

19

DSR

RI

SCT

LL

RL

ST

78

21

79

24

17

22

1Y

2Y

3Y

4Y

1A

1B

2A

2B

3A

3B

4A

4B

SEL

"0" = DTE

"1" = DCE

SCC

61

SD(A)

SD(B)

TT(A)

TT(B)

TR(A)

TR(B)

RS(A)

RS(B)

RT(A)

RT(B)

RD(A)

RD(B)

CS(A)

CS(B)

RR(A)

RR(B)

DM(A)

DM(B)

SCT(A)

SCT(B)

IC(A)

IC(B)

LL(A)

LL(B)

ST(A)

ST(B)

SP503

DTE

Config.

SP503

DCE

Config.

59

63

65

58

56

54

52

70

71

37

38

66

67

35

36

68

69

76

77

39

40

51

49

42

44

61

59

63

65

58

56

54

52

70

71

37

38

66

67

35

36

68

69

76

77

39

40

51

49

42

44

47

RL(A)

47

3

16

17

9

6

22

5

13

2

14

24

11

4

19

18

20

23

21

8

15

12

22

10

TxD

TxC

DTR

RTS

RxD

RxC

CTS

DCD

14

15

13

16

1

20

80

19

DSR

RI

SCT

LL

RL

ST

78

21

79

24

17

22

SD(A)

SD(B)

TT(A)

TT(B)

TR(A)

TR(B)

RS(A)

RS(B)

RT(A)

RT(B)

RD(A)

RD(B)

CS(A)

CS(B)

RR(A)

RR(B)

DM(A)

DM(B)

SCT(A)

SCT(B)

IC(A)

IC(B)

LL(A)

ST(A)

ST(B)

RL(A)

LL(B)

7

1