serial port with Windows NT

[Werner Lentz]

Hi,
I have a program, written in PB3.5, wich uses the com port for
communication with a PLC. This program works fine with DOS.
Now I've upgraded the computer and it's now running with Windos NT.
The communication doesn't work anymore, even nothing was changed.
Here is a snippet of the code, used in the program.


x%=freefile
OPEN "COM1:9600,E,8,1" AS #x% LEN = 1024

dle=&H10
stx=&H02
etx=&H03
ret=-99

start=timer
print #x%,chr$(2);
do 'dle lesen
loop until loc(x%)<>0 or timer-start>1
if timer-start<1 then sps$=input$(1,#x%)
if timer-start>1 then
close #x%
exit sub
end if

print #x%,chr$(0);
print #x%,chr$(0);
and so on...

I'm not quite shure what the problem is because some posts said
that progrtams using com ports should run with Windows NT.
But I have the feeling that it might have something to do with
the security philosophy of NT.

Can somebody help or clear the situation?
Best regards
Werner

------------------
Werner Lentz
[email protected]

[Mel Bishop]

Originally posted by Werner Lentz:
...I've upgraded...with Windos NT...

I think you answered your own question

I haven't played with nt so I don't have an answer for you
except to say that windows is rather autocratic for system
resources.




------------------

[Tom Hanlin]

Comm port handling is not one of the areas that should give a DOS
program problems under NT. You should look at other areas, like...
Is the hardware firmly connected? Do you have a COM1 port available?
If so, is it "enabled" in the BIOS setup? And is there anything else
that may be taking over the port, like the Windows fax driver?

------------------
Tom Hanlin
PowerBASIC Staff