[<<Previous Entry]
[^^Up^^]
[Next Entry>>]
[Menu]
[About The Guide]
COM_SOFT_R()
Tests to see if an XOFF character has been received
------------------------------------------------------------------------------
Syntax
COM_SOFT_R(<nComPort>,[<lXOFFFlag>]) --> lXOFFFlag
Arguments
<nComPort> Designates the port (1 to 4) for which the XOFF flag is
tested.
<lXOFFFlag> Designates whether the flag is set (.T.) or reset
(.F.). The default value (.F.) resets the flag.
Returns
This function returns .T. after the last inquiry or after you open the
port when the port has received an XOFF character (Ctrl-S).
Subsequently the port does not receive an XON character (Ctrl-Q).
Description
If the software handshake is turned on, the receipt of an XOFF character
is noted with an internal flag. This flag can be queried using
COM_SOFT_R(). The receipt of an XON character resets that flag again.
Since in some situations an XON character is never transmitted by the
remote station, the flag can be reset using the second parameter.
Note
. If incoming XOFF characters are monitored, then it is best to
transmit relatively small strings through COM_SEND(). You can use
COM_SOFT_R() to monitor between incoming XOFF characters.
Examples
. First open the port:
COM_OPEN(1, 1000)
. Transmit until an XOFF character is recognized:
nPos := 1
DO WHILE .NOT. COM_SOFT_R() .AND. nPos <= LEN(cString)
COM_SEND(1, SUBSTR(cString, nPos, 1))
nPos := nPos + 1
ENDDO
See Also:
COM_SEND()
COM_SOFT()
This page created by ng2html v1.05, the Norton guide to HTML conversion utility.
Written by Dave Pearson