Instruction Manual

PLC programming
Library
V24 functions
8
8.8
8.8.2
l
380
EDSTCXN EN 2.0
8.8.2.7 WRITEV24
FUNCTION WriteV24: DINT
VAR_INPUT
req_pr : DINT; (* Address of the V24 request structure *)
chr_di : DINT; (* character to be written *)
END_VAR
Writing a character into the send buffer. The send buffer is implemented as
FIFO and is read and written a character at a time.
This function always provides an immediate return even if the FIFO is full. In
this case the character will not be written and −1 (EOF) will be returned.
Generally a return value of less than 0 indicates an error (¶ 391).
requestV24_p : DINT;
zeichen_di : DINT;
ret_di : DINT;
zeichen_di : = 65;
ret_di
: = WRITEV24(requestV24_p, zeichen_di);
8.8.2.8 CLRRXBUFFER
FUNCTION ClrRxBuffer: BOOL
VAR_INPUT
req_pr : DINT; (* Address of the V24 request structure *)
END_VAR
This function can be used to delete the reception FIFO completely.
The return value of the function is of no consequence.
requestV24_p : DINT;
requestV24_p : = ALLOCV24(1, 127);
CLRRXBUFFER(requestV24_p);
Declaration
Description
Example
Declaration
Description
Example