Pepper Computer RS232 Benutzerhandbuch

SMART I/O User’s Manual

©1996 PEP Modular Computers GmbH

March 12, 1996

Page 6 - 13

Chapter 6  Communications Modules

A complete list of the operate 

COMMANDS

 may be obtained by selecting a

project from the ISaGRAF projects group, opening an application and

observing the Common defines in the Dictionary pull-down menu. Note that

not all calls in the list may be used within the SMART I/O environment

however, the calls applicable to this module are :

: The syntax and usage have already been explained.

: This operate call prevents the system from being

 blocked due to polling of incoming characters.

 Hence, during every ISaGRAF cycle, the program

 checks if the buffer for incoming data contains data.

 If so, the data will be collected. The syntax is as

 follows:

<chars_in> := OPERATE(<ser_in>,O_SERIAL_READ,<chars>);

where

<chars_in>

represents the actual number of characters

read from the buffer.

<ser_in>

is the input device name.

<chars>

the number of characters expected to be read.

ret := OPERATE(keyboard, O_SERIAL_READ, 10);

If the default value 0D hex is used for the 

eor_char

 then the scanning of

the input will terminate when either the <RETURN> key is pressed or 10

characters have been read.