|
By design, USB has a cable length limit of 5 metres.
You are able to use up to 4 cables extenders to increase the distance to 25 metres, but no futher. So if your device is located more than 25 metres from your computer, USB is not the way to go. As far as I know, Firewire does not have this cable length problem.
My advise is to read the USB specification carefully and make sure the USB is the solution for your device, it does have some very important limitations.
|
|
|
|
|
Thankyou, this was not an issue I was aware of. Though that should be more than adequate for our device.
I have downloaded volumes on the USB specification and look forward to a little light reading!
--
The Obliterator
|
|
|
|
|
>> However of late I see COM ports are to be abolished mid-next year
Funniest thing i've heard all day.
Admittedly, today has been a bit slow. But that's utter chud anyway. People still use COM ports for Modems and stuff. And serial connections to telco apparatus. And most POS equipment is RS-232 (tils, receipt printers, barcode readers etc)
Sorry to dissapoint you all with my lack of a witty or poignant signature.
|
|
|
|
|
Well, I hate to be the bearer of bad news, but Intel has publicly stated that they're going to abandon of "legacy device" support within the next year or so. This means bye bye to serial ports, parallel ports, PS/2 mouse ports, keyboard ports, etc.
I guess they want to throw everything onto the USB bus. It would certainly make for more efficient chipsets, but it would also force everyone to update their admittedly aging array of legacy devices. If Intel abandons these ports, you can most assuredly count on Microsoft following suit in subsequent versions of Windows.
To hell with those thin-skinned pillow-biters. - Me, 10/03/2001
|
|
|
|
|
COM ports will be around a LONG LONG LONG LONG time. Might not be available on your standard PC system, but you will always be able to get them as addons.
Too much stuff needs a COM port.
Tim Smith
Descartes Systems Sciences, Inc.
|
|
|
|
|
Yes I would tend to agree... but it makes it difficult to sell our kit if nots easy to use and connect.
--
The Obliterator
|
|
|
|
|
I don't find it funny... my day has gone from bad to worse!
Whilst trawling around for USB info I read an extract from an Intel article clearly stating they plan to withdraw all legacy support. This includes serial, parallel and floppy drives!
They expect all users to use USB compliant devices instead.
Just how you are expected to repair Windows when it all goes pear shaped in the future I have no idea!
>>Funniest thing i've heard all day.
>>>> However of late I see COM ports are to be abolished mid-next year
--
The Obliterator
|
|
|
|
|
FWIW, there are devices that connect to the USB and provide serial ports. I spent a few minutes looking through a PC Connection catalog and I found units from Belkin, Comtrol, Keyspan, Targus, and Tripp-Lite and they do not appear too expensive.
There are also software packages available to help with USB driver development. I think Blue River Systems has one and there are a few others.
Best of luck.
|
|
|
|
|
Yes this was really part of my original question, thankyou.
I couldn't understand how an adaptor would allow the software to work without custom software mapping the USB as some kind of virtual COM port. Clearly this is the case, and I may explore these options as a short term fix. For anyone else with similar problems here is one such solution:
http://catalog.belkin.com/IWCatProductPage.process?Product_ID=66002
As for Blue River Systems, I will have a hunt for their stuff now and see whats on offer. Thanks.
--
The Obliterator
|
|
|
|
|
One of my first vc++ applications...
What is the best way to open new windows 'in' an existing child window in a VC++/MFC/MDI application ? (e.g. based on MS VC++ sample 'mdi', with the 'hello' and 'bounce')
My application should open a child window (window_1).
Clicking in window_1 would result in a new child-of-child window inside window_1 (window1_1, window1_2 etc.)
Once that is working, I would like to draw a line between the windows. (e.g. arrow from border of window1_1 to border of window1_2)
If you have any solutions, pointers to code/doc etc. it will make me so very happy !
|
|
|
|
|
float fAngle = atan(1);
what's wrong with this? I don't get any reasonable values out of the atan function! There's nothing wrong with assigning a double to a float is there? Tried this also, gave the same crap:
float fAngle = (double) atan(1);
As far as I know, the outcome of this function is supposed to be 45. Sorry if I come over a bit angry, I am
I spent half the day trying, so please help
WAVK
|
|
|
|
|
atan accepts a double, and returns a double
try this:
float fAngle = (float)atan(1.0);
although, I would really look into changing the type of fAngle to double.
To hell with those thin-skinned pillow-biters. - Me, 10/03/2001
|
|
|
|
|
I've beenn trying too long and so my stupid head converted a double to a double instead of a float thanks for clearing me up
WAVK
|
|
|
|
|
The result is supposed to be Π/4 because the result is in radians, not in degrees.
|
|
|
|
|
Hi wavk;
atan(1) is 45, as long as 1 is in degrees.
All the trig functions in C are in radians which give you 0.785...
This might be your problem.
|
|
|
|
|
i've recently installed win2k. now, when i use class wizard to add a message handler, when i hit OK, i get a message about how VC was unable to copy this or that temp file, or that the file CW was working on was unable to be written, etc..
has anyone else seen this?
could it be related to NAV?
-c
Smaller Animals Software, Inc.
http://www.smalleranimals.com
|
|
|
|
|
I don't have any problems (not running NAV, though). Are the resource files resource.h and app.res) read-only?
To hell with those thin-skinned pillow-biters. - Me, 10/03/2001
|
|
|
|
|
nope....
it usually happens on the .CPP for the window i'm working on. more than once, it's told me that it can't write the CPP (after adding the new message handler) and that my only chance of recovering the .CPP is to go out and look inside a particular temp file. scary sh*t.
-c
Smaller Animals Software, Inc.
http://www.smalleranimals.com
|
|
|
|
|
Chris
I am using VC++ 6 SP5 on Win 2000 SP2 with NAV Corporate. I won't lie and say I do heaps of development but I have not run into this problem.
Did you upgrade to Windows 2000 over some earlier operating system? Or did you mean upgrade as in new machine and OS?
When you say message handlers you mean like ON_CLICK for a buton (as a weak example)?
If you give a little more detail I will try to reproduce on my installation.
Michael Martin
Pegasystems Pty Ltd
Australia
martm@pegasystems.com
+61 413-004-018
"Don't belong. Never join. Think for yourself. Peace"
- Victor Stone
|
|
|
|
|
new machine with Win2K pre installed, vc 6 (sp 5, i think), new Dell P-4 1.7.
When you say message handlers you mean like ON_CLICK for a buton (as a weak example)?
yep. it seems to happen pretty much any time CW has to write into a .CPP file - message handler, Afx* override, etc.. it looks like CW copies the original .CPP to a temp file, modifies the temp, deletes the original then copies the temp to the original's place. only, on my system, it sometimes fails to delete the original, or fails to copy the temp onto the original. sometimes it tells me it can't write the .CPP because some other app is using the file.
i've got NAV set so that it doesn't scan .CPP or .H files, so i'm not sure it's the problem. but, NAV is the only other app i can think of that would be opening files without consent.
-c
Smaller Animals Software, Inc.
http://www.smalleranimals.com
|
|
|
|
|
I am using MFC without the Doc/View architeture, its a dialog based WinCE application. Anyhow, I use Structured Exception Handling, if any exception occurs the software reports out the exception information, I then want to kill the software as cleanily and quickily as possible.
Best way of doing this pls ?
Regards
Ray
"Je Suis Mort De Rire"
|
|
|
|
|
Ray
Try PostQuitMessage(0); , that should do the trick.
Norm Almond
Chief Technical Architect
FS Walker Hughes Limited
|
|
|
|
|
I can't remember how to get a Program to play a sound, It was like playSound("ss.wav.") somthing like that .
One more thing, I need a way to change the titel(Caption) In a dialog window, in the program while it is running, how?
Thank you
|
|
|
|
|
>I can't remember how to get a Program to play a sound, It was like playSound("ss.wav.") somthing like that
PlaySound defined in Winmm.lib MMSystem.h
>One more thing, I need a way to change the titel(Caption) In a dialog >window, in the program while it is running, how?
SetWindowText
Michael
|
|
|
|
|
you are chasing PlaySound(LPCTSTR) ...
Regards
Ray
"Je Suis Mort De Rire"
|
|
|
|