Ret = OPERATEkeyboard, Oserialread | Pepper Computer RS232, RS485

Chapter 6 Communications Modules	SMART I/O User’s Manual

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 :

O_INIT_CODE : The syntax and usage have already been explained.

O_SERIAL_READ : 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>

<ser_in> <chars>

represents the actual number of characters read from the buffer.

is the input device name.

the number of characters expected to be read.

	Example
	Example	6
	ret := OPERATE(keyboard, O_SERIAL_READ, 10);	6
	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.


March 12, 1996	©1996 PEP Modular Computers GmbH	Page 6 - 13
		Page 6 - 13

Pepper Computer RS232, RS485 user manual Ret = OPERATEkeyboard, Oserialread

Models: RS485 RS232

Chapter 6 Communications Modules

Example

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