From: lynch@cci.de
Subject: Win NT + Object Ada: serial port I/O
Date: 1999/02/03
Date: 1999-02-03T00:00:00+00:00 [thread overview]
Message-ID: <79952r$2t$1@nnrp1.dejanews.com> (raw)
Hi,
I have been asked to write a DLL which will be used to talk to a display (LCD)
connected via an RS-485 serial line (DIN 66 019 protocol). The card apparently
comes with a driver which makes it act like a standard COM-Port.
Rather than fork out the $XXX for something like Visual C++ (and a new HDD) I
would like to develop using the Object Ada we already have.
Does anyone have any information/experience programming serial ports in Ada on
a Windows platform? I can think of two ways to do this:
1) Use the standard Ada.*.IO routines on the file "COM1:". I tested this with
a VT420 on the other end and came across two problems:
a) It seems the port needs to be "initialized" by calling MODE COM1: in a
console window, even though the settings are exactly the same as those
in the windows control panel.
b) I need a timeout capability for the reply from the LCD/Terminal.
Using Get or Get_Immediate without "Available" blocks indefinitely,
all attempts to use Get_Immediate with loops and timers have failed.
(Available seems to be _always_ false!?)
2) Use the Win32Ada binding with CreateFile, SetCommTimeouts etc. however the
help file provided with Object Ada is utterly useless. I have yet to find
the section which "describes [...] the transformation rules (from C to Ada)"
Also the guy who will be using this DLL is worried about all the type
conversions etc. ("why use an Ada compiler if you're writing C anyway...")
Are there any alternative (higher-level) "COM-Port"-Bindings available?
All I need to do is write a stream of ASCII characters and read characters
with a timeout after x ms, in case somebody pulled the plug or whatever.
If anyone has some sample code that accesses a COM-port using Object Ada
I would be most grateful for a quick peek at it! (This is my second-ever
MS-Windows project, I hope it will be my last...)
Cheers,
Andrew.
-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
next reply other threads:[~1999-02-03 0:00 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-02-03 0:00 lynch [this message]
1999-02-03 0:00 ` Win NT + Object Ada: serial port I/O news.oxy.com
1999-02-04 0:00 ` lynch
1999-02-04 0:00 ` news.oxy.com
1999-02-04 0:00 ` dennison
1999-02-04 0:00 ` Tom Moran
1999-02-16 0:00 ` lynch
1999-02-16 0:00 ` dennison
1999-02-16 0:00 ` David C. Hoos, Sr.
1999-02-16 0:00 ` dennison
1999-02-16 0:00 ` dennison
1999-02-17 0:00 ` Peter Hend�n
1999-02-16 0:00 ` Steve Doiel
replies disabled
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox