how to create interface for the tekscan bpms device with the labview

[sukumar]

can any one tell me how to develop system for the Tekscan BPMS( Body Pressure Measurement System) with the Labview. Thanks in advance.

[smercurio_fc]

What exactly are you trying to do? Write an application or write a driver for this? I assume is some sort of instrument, since you didn't say what it is.

[sukumar]

Ya you are write. Tekscan BPMS is a instrument which is a interface between the pressure sensing mat and the computer. I want the pressure signals coming from the device to be taken by labview and do some analysis and display the output. Can you please tell me how to do that or in general for any device?

[Dennis_Knutson]

There is not such thing as 'in general for any device'. There are a variety of interfaces that are possible between devices and a computer - GPIB, RS232, USB, Ethernet, and more. For some of these, you can use a generic VISA Read/Write but it really depends. What kind of interface does this thing have?

[smercurio_fc]

So you basically need an instrument driver. There's no pre-written drivers available from the NI list of available drivers. What does the manufacturer provide? What kind of interface does this have? Is it serial, or is it some sort of digital/analog signal?

How much LabVIEW experience do you have? It sounds like you're just starting out. If so, you should go through the documentation and tutorials available with LabVIEW first so you understand the language. This link provides general guidelines on writing an instrument driver if this thing has some sort of communication interface.

EDIT: Sorry for the double answer. Written at the same time that Dennis was providing his answer.

Message Edited by smercurio_fc on 06-26-2007 03:41 PM

[sukumar]

It has got the USB interface.I want to build the system for it. Like I want to take the signals that are coming out from the device by the labview and I want to analyze and display the thing. What should I do for it?

[Dennis_Knutson]

Okay, we've narrowed it down a bit. First, there is no generic USB communication. The interface might emulate a serial port. If that's the case, then you can find the commands in the manual and implement some remote control. Look at the shipping examples related to serial. Some vendors implement what is called USBTMC. The TMC stands for Test & Measurement Class. With this, instruments are programmed in a manner similar to GPIB. There are commands and queries that would be documented in the manual. Like serial in LabVIEW, the communication is based on VISA. There is a tool called the Instrument I/O Assistant that helps with developing your program. The vendor may also create something more proprietary. Referred to as USB RAW, in theory, it is possible to use VISA to communicate, but in practice, it's often impossible because the vendor does not publish the low-level protocol that you need. With USB RAW, it's often better to use the Call Library Function node to access the driver DLL that the vendor provides. For more information on USBTMC and USBRAW, you can read http://zone.ni.com/devzone/cda/tut/p/id/4478. To determine what to use, you need to contact the vendor or see what the manual says. If you have an electronic version of the manual, you can post it or a link to it.

[sukumar]

k answer  this question. i have got the usb device .i want the digital signal coming from that to be acquired by the labview and do some processing. how could i acquire the signal from that. and i will connect that device through usb to the computer. and mind that signal coming from that is digital...pls reply soon...

[Dennis_Knutson]

I know what you want to do, I just don't know how because you haven't answered the question about how the vendor has implemented the USB interface. Unless someone who has used this posts and answer, you probably know more than anyone here. You presumably have the manual at least. I went to the vendor's web site and could find no useful information. There is no 'generic' solution to USB as I have already mentioned. If there is nothing in the manual, you will need to contact the vendor and ask how to interface to their hardware with a different program than what ships with it. You don't even need to mention LabVIEW. Any example, in any programming language will be a start.

[sukumar]

This is the message that was replied by them when I ask about "How to interface the hardware with a different program than what ships with it." Can u please tell me what to do next. I have attached the documents with this mail.

You would need to use one of the two API products that Tekscan sells. 

API-1 allows a program you write to get the digital output directly from the Handles (without going through the BPMS software at all).  API-2 allows a program you write to get the (equilibrated and calibrated) data from the BPMS software.  There is a DLL that make data from API-2 available to Labview.

I have attached manuals for these products.