COM Port Libraries

[Michael B Cone]

I have an application that requires very fast handling
of the COM port (RS-232) control lines (like RTS/CTS)
in order to send and retreive characters through the COM port.

To accomplish this, my goal is to use a single board
computer running DOS and a Powerbasic program. (Windows
handling of the COM port is generally not fast enough.)
Is it possible with Powerbasic to switch the control lines
(like switch RTS on and off)? Also, I need to detect when
CTS is high of low.

If this is possible, then can you point me to the
correct section in your manual that discusses these
feature. If it is not, then can you recommend a COM
library that will enhance Powerbasic so that it can
handle these lines?

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[This message has been edited by Michael B Cone (edited October 21, 2003).]

[Michael B Cone]

I just discovered the Marshallsoft and TeraTech
libraries for Powerbasic RS-232 communications.

MARSHALLSOFT
Looking through their sample code, I can see that
Marshallsoft libraries handle the control lines
in both directions.

For example Marshallsoft uses these functions:

DECLARE FUNCTION SioCTS(BYVAL Port AS INTEGER) AS INTEGER
DECLARE FUNCTION SioDCD(BYVAL Port AS INTEGER) AS INTEGER
DECLARE FUNCTION SioDSR(BYVAL Port AS INTEGER) AS INTEGER
DECLARE FUNCTION SioDTR(BYVAL Port AS INTEGER, BYVAL Cmd AS WORD) AS INTEGER
DECLARE FUNCTION SioRTS(BYVAL Port AS INTEGER,BYVAL Cmd AS WORD) AS INTEGER

TERATECH
However, according to the documentation, TeraTech only
reads the lines that are typically observed only (like DSR).
It does not appear to allow the changing of the outgoing
control lines. (Please correct me if I'm wrong on this.)


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[This message has been edited by Michael B Cone (edited October 21, 2003).]

[Herman Kieskamp]

Check IOCTL and IOCTL$, they might answer your question !!

Herman.


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You gotta run, and don't loop back.