Turning Ideas Into Reality

ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104

Part Number SIOA7

Copyright © 2014 ABCircuits. Revised September 2014 Page 6 of 10

Pin Description

Pin #

Description

Pin #

Description

1

RXP

28

VDD

2

ADR3

27

TXE

3

ADR1

26

ADR2

4

SOUT-

25

ADR0

5

NC

24

SIN-

6

OA5

23

OA6

7

OA3

22

OA4

8

OA1

21

OA2

9

NC

20

OA0

10

NC

19

NC

11

IA5

18

IA6

12

IA3

17

IA4

13

IA1

16

IA2

14

VSS

15

IA0

OA0-6

These output bits are set when a byte is received on the SIN- pin after a matching address byte is

received on the SIN- pin. Output drivers may be required for high power loads. The RXP pin

generates a positive pulse after these bits are set.

SIN-

This is the serial input pin. It may be tied directly to the UART transmitter output of your UART or

microprocessor; to a RS -232 receiver such as the MAX232; an Ethernet interface such as the

Lantronix Xport; or a USB IC such as the FT232. This pin is high in the idle state, the input

format is 8 bits, 1 stop, no parity at 9600 BPS. Other formats and baud rates are available,

please contact the factory for information. After a matching address bye is received on this pin

the next byte received on this pin will be transferred to the OA0-6 pins if bit 8 is zero, then a

positive pulse is generated on the RXP output. This pin does not have an internal pull up resistor.

If you are using a receiver with tristate outputs, such as the 75176 for RS -485, a pull up resistor

will be required. It is recommended your software periodically send the address byte and second

byte containing the OA0-6 byte even if they have not changed to recover from communications

errors or power failures.

To be a valid address byte, bit 8 must be 1, bits 7,6, and 5 must be 0; and bits 4 to 1 must match

the address pins. Bit 8 must be 0 to be transferred to the OA0-6 pins.

You can drive this input with any hexadecimal terminal program like REALTERM for testing and

development.

SOUT-

This is the serial output pin. It is open drain with an internal pull up resistor, so more than one

SOUT- pin may be directly tied together. It may be tied directly to the UART receiver input of

your UART or microprocessor; to a RS -232 driver such as the MAX232; an Ethernet interface

such as the Lantronix Xport, or a USB IC such as the FT232. After a matching address byte and

the byte for the OA0-6 pins this pin sends the data on the IA0-6 pins, adding start and stop bits.

This pin is high in the idle state, the output format is 8 bits, 1 stop, no parity at 9600 BPS. Other

output formats and baud rates are available, please contact the factory for information.