labview (serial port from usb)

[Giuseppe]

Hi,

last week I make one labview program for read with serial port the
temperature sensor . This program is ok, and running (I used serial port of
pc).

Now, today I try use notebook. The notebook have not a serial port but usb
port; I buy one usb to serial interface, I installed it but the previous
program dont work.

What is the difference betheven a official pc serial port and one serial
port from usb notebook port?

what thing can change for work a program in notebook?

Many thanks in advance

Giuseppe

[AndrewAlford]

Check the port designation of the USB to serial converter. I have used one that defaulted to COM6 when ever the notebook was powered up.

[tst]

USB to RS232 converters create a virtual port in your operating system. You should make sure that you chose the correct port in your LV program (I believe you'll need to restart LV after connecting the USB device before you'll see the port in the VISA resource list) and that all the serial settings are configured correctly both in your program and in the OS (Control Panel>>System>>Hardware>>Device Manager in Windows).

Normally you can configure the port using VISA property nodes, so there shouldn't be any need to configure the device in the OS as well.

[zola]

If your USB to serial converter is not NI's Product, debug your vi ,seeing about the VISA Error message, Status is flase ,but Error Code is not zero! 

[Giuseppe]

Thanks for reply, but the problem is not it. I choise the true port , I have
only one.
But the program dont work!!!
what is a problem...???

thank in advance

giuseppe

"tst" <x@no.email> ha scritto nel messaggio
news:1166652607666-456850@exchange.ni.com...
> USB to RS232 converters create a virtual port in your operating system.
> You should make sure that you chose the correct port in your LV program (I
> believe you'll need to restart LV after connecting the USB device before
> you'll see the port in the VISA resource list) and that all the serial
> settings are configured correctly both in your program and in the OS
> (Control Panel&gt;&gt;System&gt;&gt;Hardware&gt;&gt;Device Manager in
> Windows).
> Normally you can configure the port using VISA property nodes, so there
> shouldn't be any need to configure the device in the OS as well.

[Dennis_Knutson]

Simply saying that the program doesn't work is not enough information. When you run the program, do you get any errors? If so, what is the error code? Is the port visible in MAX? What is the make and model of the converter? Some work better than others. Search the LabVIEW and Instrument Control forums for USB to Serial and you will find a lot of posts on various maodels and what was necessary to get some of them to work.

[xradian]

To begin with I would use HyperTerminal to check if the USB -> Serial -> Sensor connection exists. Like someone stated above using a Serial to USB hub usually changes which port you are connected to.

Message Edited by xradian on 12-21-2006 12:08 PM

[MQI]

I found that some USB to RS-232 require driver installation.  Try to install the driver that comes with the device to see if it work.

[Jeff Again]

Hi,

When you use USB to Serial Converter then it's like your giving USB connectivity to your PC but latter it will convert to Serial by that converter. So it means at Laptop side you have USB device only but if you want to link any Serial (RS232) software/application with this USB to Serial Converter then you need two types of Driver

1) USB device driver for that converter

2) VCP i.e. Virtual COM Port, Which will create one virtual COM Port for your Software application and link it to USB Physical port

   Generally it will create COM port with Address COM4, COM6 like that. So you need VCP which will be dedicated for that USB to Serial Converter.

ALL the Best  :manwink:

[kehander]

I can recall one occasion in which I worked with a USB-to-serial adapter and just couldn't get it to work correctly.  I think they might not have adequate flow control for some situations.  And since many brands use the same chipset, using a different brand might not help much.

Your best option may be to get a PCMCIA serial card.  These are available quite cheaply from eBay.

(Whoops, this is a rather old thread, isn't it?)


Message Edited by kehander on 11-05-2007 01:34 PM