PEP Modular Computers Modular Computers RS485 User Manual page 295

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 :
O_INIT_CODE
O_SERIAL_READ
<chars_in> := OPERATE(<ser_in>,O_SERIAL_READ,<chars>);
where
Example
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.
March 12, 1996
: 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:
represents the actual number of characters
<chars_in>
read from the buffer.
is the input device name.
<ser_in>
the number of characters expected to be read.
<chars>
©1996 PEP Modular Computers GmbH
SMART I/O User's Manual
6
Page 6 - 13