|
Actually, this also happens with capacitors manufactured by well-known companies with an intact QA-department.
You can call this a case of capacitor plague ONLY if the capacitors fail spectacularly and prematurely. Since the capacitors contain an electrolyte and are rated for a specific MTBF at a given temperature, they can break if they are used outside their specified temperature window. If the capacitor is rated for 10 years at 30°C, it might well fail after 5 years in 35° or 2 years in 40°, depending on the specifications used by the manufacturer.
The drop in lifespan is quite dramatic for a small increase in temperature, and the result can also involve ruptures at the predetermined breaking point when all the electrolyte is gone. This does not necessarily mean that the capacitor was badly made, but just that it was not designed to operate under this conditions.
-- modified at 6:50 Thursday 17th August, 2006
Cheers,
Sebastian
--
Contra vim mortem non est medicamen in hortem.
|
|
|
|
|
I want to use Visual C++ for control hardware via RS232 or USB port.
Anyone know what is the good book or website which I can get the infomation about this issue.
|
|
|
|
|
Max++ wrote: website which I can get the infomation about this issue.
Google, AFAIK there are not many dedicated sites. The MSDN Library has a good article on reading and writing data to and from the COM ports (sorry can't remember the title). Most USB drivers come with something that will allow the USB port to look like an RS232 port with a higher baud rate. So generally all you need to know is how to read and write data to and from RS232 ports.
Regarding actually controlling the hardware you'll have to provide more information.
Formula 1 - Short for "F1 Racing" - named after the standard "help" key in Windows, it's a sport where participants desperately search through software help files trying to find actual documentation. It's tedious and somewhat cruel, most matches ending in a draw as no participant is able to find anything helpful. - Shog9
Ed
|
|
|
|
|
Can u give some more info reg ur requirements?.If u want to control ur hardware with RS232/USB u need to create handle to ur device then u can do read/write to ur device.For that u should know the command formats supported by ur device.Is it a printer/storage/camera or any thing else?.
If u give give more details i will be able to provide more info.
regards
Vairavan
|
|
|
|
|
Was that intended for me or for the thread-starter?
Formula 1 - Short for "F1 Racing" - named after the standard "help" key in Windows, it's a sport where participants desperately search through software help files trying to find actual documentation. It's tedious and somewhat cruel, most matches ending in a draw as no participant is able to find anything helpful. - Shog9
Ed
|
|
|
|
|
Sorry,Its intended for thread starter.
regards
Vairavan
|
|
|
|
|
I have several programs on the go, which ultimately need to interface with Hardware at a very basic level. e.g.:
A Salescounter Program, which needs to open the Cash Drawer, and monitor it's closure.
A Laundrette Program, (NOT DRYCLEANERS) in which each Washing Machine is monitored by a thread, and, in which each thread needs one Analogue input(16 Bit), and about 8 Digital channels in and 8 Digital channels Out.
I am not at this stage puting a Limit on the Number of Computers required, but, am thinking along the following line:-
One Computer per Sales Point(each Needs to Control a Cash Drawer)
One Computer to Drive the Interface cards to drive the washing machines.
What Off the Shelf hardware(And Firmware and Software) is available to implement this!
LateNightsInNewry
|
|
|
|
|
Well, you can buy USB analogue/digital I/O components, but bear in mind that typically they have a ~20ms delay on processing commands (eg writing takes 20ms, reading another 20ms).
In terms of firmware/software, you're pretty much on your own; you get a DLL and/or device driver to allow you to configure the I/O and read/write it, and that's it, although generally speaking you can then use them from any C/C++/VB app.
Are you looking at cash drawers as well? AFAICR, these are available off the shelf, with an input to force an 'open' and an output to report the 'closed' state.
Integrating all these won't necessarily be pretty, and you may find that there are limits on how many devices you can use from a single PC. I've used a small Velleman kit for USB I/O (which has fewer I/O lines), for example, and you can only connect 4 such devices on the USB bus, even going via a powered hub.
Steve S
Developer for hire
|
|
|
|
|
Thanks steve.
The question is where, from whom,at what price! I would accept the 50 ms delay,(Ido not think that staff would notice that the delay between hitting the Chash Button, and the drawer opening) and Four Cashdrawers per terminal suounds fine. I've given up on USB for apps like this, because the development in this are seems to concentrate on speed! I could give you thousands of development applications for anyone who would develop a USB unit, which could switch say 100 relays, with a delay of say 500 ms quite acceptable! Most real world applications, like switching of the Air Conditioning, do not require split second timing!
Where are Cash Drawer boards and API's to run same available off the shelf?
Names, Addresses,Costs
Many thanks for your support
Regards
LateNightsInNewry
|
|
|
|
|
Well, last time a company I know needed one, they did a google on 'USB digital I/O' and then it was a case of price shopping. With the advent of stuff like small microcontrollers with USB built-in, they are becoming more widely available. The Velleman ones I have (which have fewer I/O lines, I think 5 in and 8 out, but does have analogue too) I bought from Maplin Electronics, who periodically put them on sale prices (in both kit and prebuilt forms). Don't know if they operate in Ireland, though, but there ought to be an equivalent.
Some of the more expensive stuff includes optoisolators etc to stop any 'accidents' from frying USB host controllers in the PC etc. I prefer USB because it makes it easier to demo stuff from a laptop, which you can't exactly plug cards into 
OTOH, it does limit the number of lines, but being able to plug in more than one device can help make up for it.
Don't know about cash drawers, but again, google should be able to help, just a question of finding the right buzzwords (cash/terminal/drawer/POS etc). There is a company I did some Win32 training for in Otley, W.Yorks; they make POS stuff (called, amazingly enough, Point of Sale Systems), but that was a while back. They might know, so I'll see what I can find out...
Steve S
Developer for hire
|
|
|
|
|
They use cash drawers which are RS232 or USB. I think google is your best bet...
Steve S
Developer for hire
|
|
|
|
|
Roughly a decade after usb was released to do so, the legacy ports are finally starting to be removed from PCs. If you go with rs232 now, you run the risk of not having easy access to new hardware a few years down the line.
|
|
|
|
|
Yup. I have a serial port programmer for Microchip processors, and sadly, I don't have a serial port on my laptop...
Fortunately, my desktop machine does have such a thing, and I very rarely need to reprogram one on site...
Steve S
Developer for hire
|
|
|
|
|
They;re starting to disappear from desktops as well. I looked about 6mo ago, and about 1/3rd of the mobo brands on newegg no longer had serial, parallel, or game ports. Instead the space was used for even more usb ports and additional ventspace.
|
|
|
|
|
steve,
Thanks a lot for your reply. Yes, Maplin does operate in Ireland. A Cash drawer is electronically a simple but crude device. it consists of a solenoide to release the catch so that it opens, and a microswitches, which tells if it is open closed, or "No Cash Insert Present", i.e. the replacable plastic innards with pigeon holes for the Notes and coin is physically missing.
Microswitches and Solenoides typically operate at power levels far greater than provided by PC in and out ports. Most microswitches in my experience need to operate at at least 24 Volt 5 mA, to avoid long term degradation such as Dirt and Corrosion. The sparking at these lpower levels helps to keep things clean. Most solenoides for Mechanical action in this type of application take at least 24V and 50 mA . This is dictated by the scale of mechanical rigidity required to deter casual vandalism.
Again, Many thanks for your help.
Regards
BramVanKampen@aol.com
LateNightsInNewry
|
|
|
|
|
Hi,
I have a problem with a USB device in that it frequently fails when I try to connect to it to update its application. The manufacturer points out that this is a known problem and the solution is to disable and re-enable the device in Device Manager but this is, when I update the application to test something sometimes once a few minutes, a rather tedious and slow task.
The two devices, as listed in Device Manager are "Communications cable between two computers" in "Modem" and "SAGEM MONETEL EFT30 USB PORT (COM5) in "Ports (COM & LPT)".
Does anyone know how I can do this or what API I can use to do it?
Thanks in advance 
|
|
|
|
|
Each time when I plug in USB memory stick to the pc, there is a window pops out. I have application to indicate whether a USB memory stick presents.I don't want this auto window to pop out. How shall I resolve it??
|
|
|
|
|
this is a known windows 2000 bug. to fix it you need to put a filter driver over usbstor.sys that mods the response to IRP_MJ_QUERY_CAPABILITIES.
Truth is the subjection of reality to an individuals perception
|
|
|
|
|
look at the setupdixxx functions, you can enable and disable a device programaticaly.
Truth is the subjection of reality to an individuals perception
|
|
|
|
|
Thanks I'll look into it.
|
|
|
|
|
I want to control my UPS from my C#.Net program.
if you please help me.
kn
|
|
|
|
|
Are you implying you want to do it via the Serial Port? See the SerialPort class in .net 2.0. After that, you'd have to do some API searching...
/\ |_ E X E GG
|
|
|
|
|
hi,can you help me?
I have a problem with console page...
when I type cmd in "Run" bar (in start menu), it resets my computer...
thanks
maria...
|
|
|
|
|
Your probably infected with a virus or a Trojan. Scan your machine and you might come up with some interesting results!
Dave Kreskowiak
Microsoft MVP - Visual Basic
|
|
|
|
|
Sounds as if something got seriously corrupted in the Registry. Never happened to me before, but then again,I never tried 'cmd' either! I always use 'command.com' cmd is a reference to 'c:\windows\System\command.com'on my system.
If you type in the above system path, and you get the DOS Screen, there is nothing wrong with the command processor, but you should investigate.
Start with opening the Registry and search for 'cmd' , follow from there.
N.B.
The fact that you want to break into character mode (DOS Screen) makes me think that you're well used to .Bat and .Ini files
Well, those AutoExec.Bat and Sys.Ini files have gone. That information is now stored in the System Registry. Please read books about the registry, and familiarise yourself with the subject before you make any changes!
LateNightsInNewry
|
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
