1

1

2

2

3

3

4

4

5

5

6

6

7

7

8

8

A

A

B

B

C

C

D

D

RS 232

PPI

NOTE

WITH HEAT SINK

1.This converter doesn't isolate the RS232 (left) section from the RS485 section. Beware at voltage drop from one

to other earth or ground: this interface will be destroyed when discharge the current drop

2.In this drawing are not showed the power pins on ICs they are: IC1:VCC(16),GND(15) IC2:VCC(8),GND(5)

3.Please take carefully to trim RV1 for obtain 5V, start with cursor of RV1 to ground, than you must measure on output

1.25V, then get up cursor to measure 5V. Make this operation without ICs mounted to prevent destroying if

output voltage raises over 5V.

QRA.0009/01

1.0

Siemens S7-200 PPI Converter

Corrieri Gabriele

Quick reference archive

A4

1

1

Wednesday, August 07, 2002

Title

Size

Document Number

Rev

Date:

Sheet

of

+5VDC

P2

DB9 MALE

5

9

4

8

3

7

2

6

1

P1

DB9 FEMALE

5

9

4

8

3

7

2

6

1

+

C1
.01mF

+

C3
.01mF

+

C2
.01mF

DC

DC

U1

MAX232

11

10

12

9

13

8

14

7

1

3

4

5

2

6

U2

SN75176

D

4

DE

3

R

1

RE

2

A

6

B

7

D2
1N4004

D4
1N4004

D3
1N4004

D1
1N4004

D5
1N4004

1

2

DZ1
5,1 V 1/2W

R1

330

R2
3K3

R3
270

R4
270

DL1
TX

R5
1K5

DL2
RX

R6

1K5

+

C4
.01mF

+

C5

.01mF

U3

LM317

VIN

3

ADJ

1

VOUT

2

R7
220

RV1

1K