hi need a vi to communicate with a usb connecting to 4 sensors

[ashmita]

hello
          i m working with labview 7... and working on sensors(strain gauge type sensors).... my job is to communicate with a usb cable that is connected to those sensors without the help of drivers.. so i need a Vi for that.... and after that i need to physically look at the incoming data on the computer so another Vi for that... pls help me as my deadline is near

[MikeS81]

Hi ashmita,

can you please explain in more detail what you want to do? How do you connect the sensore over usb with your pc?

Mike

[ashmita]

hello mike
 thanks for the instant reply...
well i m working on INTELLIGENT BED(IN BED) ... ie there is a pateint s bed which has four sensors attached to its base .... now these sensors are connected to a signal conditioning circuit and a usb cable from that circuit connects the pc... i have to communicate with that usb

[Dennis_Knutson]

This new thread is related to this. You must have gotten a device driver from the vendor in order for the instrument to be seen by windows and for their software to work. If you don't then you should ask for it. Once you have it, you need to ask the vendor how you can use a third-party program to interface. They may provide you with an api. They may be using a dll to and you would get a description of the funciton calls in the dll. You would then use LabVIEW Call Library Function Node. If the vendor is very willing, they may provide you with the USB RAW information and then you could create a VISA driver for it. In any case, you need to start with the vendor and see what kind of information they can provide.

[ashmita]

@dennis
butthe thing is i have a vi which does not use drivers and still gets connected to the usb and initializes the system.... but now i have to modif ythat vi to make it simpler and thus see the incoming data phsically on the pc..... if u give me ur mail id i can send u the vi i have and then u could suggest me something.... btw the hardware i m talking bout are comp ports

[Dennis_Knutson]

Where did you get this VI? It has to use some sort of driver (either VISA or one from the vendor) and all you have to do is attach the VI to your post. Look below the message body. See the box labeled 'Attachment' and the 'Browse' button next to it. Just use the button to locate the VI.

[ashmita]

hi dennis
yes it uses visa... i m sending u the vi and the sub vi s also....have a look and help me furthere pls... my deadline is till this sunday...i would really appreciate ur help

[Dennis_Knutson]

If the instrument's USB connection is emulating a serial port, then this should work. One way to tell is to open MAX (Measurement & Automation Explorer) and see if you get an extra com port when you connect the USB cable.

To read the sensor values, you will need to get the commands from the vendor. It doesn't appear that anyone the forum has worked with this instrument. If it's truly emulating a serial port, it might be easier for you to test the commands in Hyperterminal first. Once you've done that, then you can use the VISA Write and VISA Read functions. You could also try the Instrument I/O Assistant. If you have an electronic copy (or can provide a link) of the command list from the vendor, you will need to post that to get some additional help.

[ashmita]

ok thanks
ill try working on wat u said.... yes the MAX does show extra port when th eusb is connected.... and one question.... wat is hyperterminal

[Dennis_Knutson]

Hyperterminal is the terminal emulation program that ships with windows (Programs>Accessories>Communications). Every instrument vendor the provides an RS-232 instrument should be familiar with it and should be able to help troubleshoot any problems you have with basic communications.