topic Re: Barcode Inputs parallely in LabVIEW

Barcode Inputs parallely

Ranjeet_Singh — Fri, 03 Jan 2014 08:44:18 GMT

Is this possible to read two barcode inputs by two different application running parallely in one CPU?

Re: Barcode Inputs parallely

D.Barr — Fri, 03 Jan 2014 09:01:51 GMT

I only have a little experience reading barcodes so i am by no means an expert.

I would guess it would depends on your barcode scanner(s). We have two types at work one behaves as a HMI device and therefore i dont think Labview can tell the difference between the scanner(s) and the keyboard. In this case i dont know of a solution.

The other type of scanner we have is older and commicates over a serial port. As the two scanners would separte serial port there would be no reason why two applications could not run on the same CPU.

Hope this helps

Re: Barcode Inputs parallely

Ranjeet_Singh — Fri, 03 Jan 2014 09:32:43 GMT

For two parallel reading barcode I need two keyfocus indicator and pass it to TRUE?

How can I make it work two indicator and both keyfocus to be true?

Re: Barcode Inputs parallely

D.Barr — Fri, 03 Jan 2014 11:32:20 GMT

If your scanner commincates over a serial port then you dont need key focus. Just create a loop that monitors serial port X until data arrives then process the data.
I am guessing your scanner behaves like a HMI device as you are talking about key focuses i am afriad your now out of my area of experience.

Good luck

Re: Barcode Inputs parallely

Ranjeet_Singh — Fri, 03 Jan 2014 12:37:00 GMT

I am aware of that.....Now a days all scanner comes with USB for your kind information.

Re: Barcode Inputs parallely

jcarmody — Fri, 03 Jan 2014 13:27:39 GMT

@Ranjeet_Singh wrote:

I am aware of that.....Now a days all scanner comes with USB for your kind information.

Right, but you can receive data from your scanners in a few ways. I have several applications that simply use a scanner as the keyboard, so the user (or, my program) needs to be sure to have the key focus set properly. I have another system that uses the USB scanner as a virtual COM port and my software monitors that for data. This doesn't require key focus to be set and lends itself well to having multiple scanners. I think that's what D.Barr was trying to say.

If you can be certain of the sequence in which the barcodes will be scanned, you can set the key focus appropriately as you recieve data. If you can't be sure of the sequence, but the formats of the bar-codes from each scanner are different, you can capture the keystroke events at the <This VI> level, make the distinction and then send the data wherever it's needed.

Re: Barcode Inputs parallely

tst — Fri, 03 Jan 2014 14:18:55 GMT

When a barcode reader is installed as an HID input device, LV treats it as a keyboard and doesn't see a difference between the various keyboards.

I haven't tried doing what you want myself, but I understand you basically need to get the data in a different way. I expect the information in this thread might be useful

Re: Barcode Inputs parallely

tst — Fri, 03 Jan 2014 14:20:51 GMT

OK, for some reason it didn't like the link. Here it is - http://forums.ni.com/t5/LabVIEW/Nugget-1-of-n-GEtting-started-with-USB-communication-via-VISA/m-p/743518#M340676

Re: Barcode Inputs parallely

Dennis_Knutson — Fri, 03 Jan 2014 14:56:41 GMT

@Ranjeet_Singh wrote:

I am aware of that.....Now a days all scanner comes with USB for your kind information.

That is simply not true.

Re: Barcode Inputs parallely

Ranjeet_Singh — Sat, 04 Jan 2014 02:47:15 GMT

@Dennis_Knutson wrote:

That is simply not true.

I had a requirement of RS232 scanner, when I asked my supplier, he simply said cannot supply becasue now a days they are all using USB

Re: Barcode Inputs parallely

Ranjeet_Singh — Sat, 04 Jan 2014 03:13:34 GMT

jcarmody,

I have one application to which I have no control. It will read the scanned number by user and search in database and process it and generates the output.

Another application is written in LV writes the SR no scanned by scanner and do some processing and update to database.

Now one application will read and another will write the data to database. In both the cases input is given by scannner to application.

Is this possible to run both application parallely in one CPU. Here the sequence of inputs is also not fixed. Both the application will read independently from different scanner.

In my end for one application I can add enter at last(already there) and for another scanner I can add TAB at last

Re: Barcode Inputs parallely

Dennis_Knutson — Sat, 04 Jan 2014 03:53:28 GMT

Haven't you used Google? A search for 'bar code scanner rs232' returns numerous results.

Since you have no access to one application, use a wedge type/ USB for that. Use an RS232 one for the second or just use the same scanner for both. With USB scanners, it's really a difficult exercise to make Windows see different ones. They are all keyboards.

Re: Barcode Inputs parallely

Ranjeet_Singh — Sat, 04 Jan 2014 07:28:59 GMT

@Dennis_Knutson wrote:
Haven't you used Google? A search for 'bar code scanner rs232' returns numerous results.

Since you have no access to one application, use a wedge type/ USB for that. Use an RS232 one for the second or just use the same scanner for both. With USB scanners, it's really a difficult exercise to make Windows see different ones. They are all keyboards.

I did that but what I mean to say is now a days nobody is buying that(Except the peoples have no choice). I never said this doesn't exists.

Regarding my question, I have a project needs to be done in this way only. Using same scanner is not possible(If I do that then user needs to bring the window to TOP all the time, becasue in one project only sr no needs to be scanned but for other some other things also needs to be scanned).

One more things I need to ask, for barcode I need cursor, if I use two USB barcode then creating two cursor is different. For RS232 scanner then use USB to serial and reading using VISA then is it good solution?

Re: Barcode Inputs parallely

Dennis_Knutson — Sat, 04 Jan 2014 07:54:18 GMT

You did say all bar code scanners come with USB.

If your users are unwilling to click on different Windows to obtain focus then the most sensible option is to use a non-usb scanner for one of them. This has already been suggested by several answers you got here. Windows itself does not differentiate between multiple USB scanners. One or many show as a single keyboard.

Re: Barcode Inputs parallely

nathand — Sat, 04 Jan 2014 16:47:38 GMT

A USB scanner does not necessarily mean it can only act as a keyboard. Many scanners can emulate a serial port by scanning a special barcode to put it into that mode.

Re: Barcode Inputs parallely

Ranjeet_Singh — Mon, 06 Jan 2014 02:50:30 GMT

@nathand wrote:

A USB scanner does not necessarily mean it can only act as a keyboard. Many scanners can emulate a serial port by scanning a special barcode to put it into that mode.

Can you please elobrate? Is it possible to write to an indicator without focus? My other application which is not written using LV needs focus so if I can able to write scanned value to my indicator without focus then all job is done.

Thanks

Re: Barcode Inputs parallely

Ranjeet_Singh — Mon, 06 Jan 2014 02:53:18 GMT

@Dennis_Knutson wrote:
You did say all bar code scanners come with USB.

If your users are unwilling to click on different Windows to obtain focus then the most sensible option is to use a non-usb scanner for one of them. This has already been suggested by several answers you got here. Windows itself does not differentiate between multiple USB scanners. One or many show as a single keyboard.

Yes when I enquired about it then my delar said no. If I can emulate the USB as serial and can write to my indicator without focus then I think it will be done.

Re: Barcode Inputs parallely

RavensFan — Mon, 06 Jan 2014 02:55:27 GMT

What is a "delar"?

Re: Barcode Inputs parallely

nathand — Mon, 06 Jan 2014 02:59:53 GMT

@Ranjeet_Singh wrote:

Can you please elobrate? Is it possible to write to an indicator without focus? My other application which is not written using LV needs focus so if I can able to write scanned value to my indicator without focus then all job is done.

Of course writing to an indicator does not require focus - an indicator displays values. I'm not sure why this is relevant here. You can read from a serial port at any time, regardless of whether the application has focus. You will have to consult the manual for your scanner to see if it supports serial port emulation. The Honeywell (formerly Handheld) scanner I used in a previous application had special barcodes to switch between keyboard emulation and serial communication. Other devices might require installing a specific driver.

Re: Barcode Inputs parallely

nathand — Mon, 06 Jan 2014 03:00:15 GMT

@RavensFan wrote:

What is a "delar"?

Dealer.