how to display EEG signal with labview

[orchid]

Hi all,

I am using Labview 7.1 with vista and USB6009. I am gonna record the EEG signal using TT-USB (Flexcomp Infiniti encoder) and want to display it on the Labview. But, I do not know how to do it. Can you help me?

Thanks,

Orchid (cruel_orchid@yahoo.com)

p/s: actually I have already post this thread on the Hi-Q, but I think I should post the message in this board. Hopefully anyone can help me

[Dennis_Knutson]

I did a google of the Flexcomp instrument and I'm not sure how the 6008 fits into your problem. It seems that the Flexcomp is the interface to the sensors and that there is a USB interface between the pc and the Flexcomp. If you could get some details on the USB interface, you should be able to connect through that and display the results. If the USB interface is emulating an RS-232 port, then you can experiment with Hyperterminal and the LabVIEW serial examples. You would need to know what commands to send to the instrument to request data. Is there a programming manual for the instrument?

p.s. Since this does not appear to be related to DAQ, you might want to post to the Instrument Control board as that would be more appropriate. HiQ was certainly the wrong board. You also don't want to publishing your email address in a public forum unless you like receiving spam.

[orchid]

I had ask the manufacturer about the TT-USB interface. He said that The USB interface is a one-way communication device that receives light-encoded sensor data from the FlexComp and converts it to serial data stream for the software to read.There are no functions that can be controlled from the software side. Do you have any schematic of how to built the VI for my case?

I have heard about VISA. What is the purpose and is it needed to display the EEG signal?

Thanks,

Orchid,

I have repost my previos question on the Instrument control as you suggested.

[TobyHex]

Hello Orchid,
Typically you would be able to control a serial device in LabVIEW by using VISA commands as shown here. The problem that you will run into is I am assuming that your device is connecting through a USB, therefore it needs to be recognized in Measurement & Automation Explorer(MAX) as USB, to be an available VISA resource. The Developer Zone Article found here will allow you to develop instrument control for this USB device. If this all sets up correctly, you should then be able to use LabVIEW to control the reading of your device's inputs, since no writes are allowed. Thanks again and have a great day!
Regards,

Nicholas K

[orchid]

I am using Labview 7.1 and NIDAQmx 8.5. I am wondering whay I did not see the NI-VISA on the MAX? So, I don't know how to recognize my TT-USB device. Do I need to replace the Labview to ver. 8?

[Dennis_Knutson]

Did you actually install NI-VISA? In MAX expand the software listing and see if it's there. Even it's there and installed, if the USB interface is emulating an RS-232 port, all that you will see is the port (i.e. Com3). If it does not emulate a com port, then you have to create a VISA driver for it yourself and use USB RAW. That is not trivial and will require substantial information from the vendor. Have they been of any help at all on how something other than their proprietary software can communicate to their instrument?

[orchid]

I have just install the NI-VISA and install my TTUSB.

They said  that the API is the tool to use because it gives  access to all the sensor data.  The API gives all the low-level functions needed to read raw unprocessed sensor data via the TT-USB and completely bypass BioGraph.

Can I know what type of signal will be read from the VISA? Is it possible in graph? As I explain earlier, I want to record the EEG signal which is suppose to be raw data.

[orchid]

I have another question...

I try to do the example usbrawbulk.vi. When I click at the VISA resource name, it have 2 option which are COM3 and LPT1. Why the USB is not appear? Then, what should I do?

 I also try USBRAWcontrol, and at the same port appear.When I choose COM3, this message pop up

Possible reason(s):

Invalid Session Type.  Next time, select a USB RAW VISA Resource.

How can I select the resouce?

Is there any example that I can try to see the output from the USB?

Message Edited by orchid on 07-09-2008 04:39 PM

[Dennis_Knutson]

Lets take a few steps back. As has been mentioned, if the USB on the instrument is set to emulate a serial port, you can use NI-VISA serial functions. It would automatically appear as a com port in MAX and in windows device manager. It doesn't sound like this is true. In order to use the NI-VISA USB functions, you would first have to create your own inf file (as described in one of the links above) and then proceed from there. When you do that, you throw away the driver and other software you got from the vendor. Using VISA USB should be considered as a last resort. The vendor told you to use their API. That is what you should do and forget all about VISA. If the API is a dll, then in LabVIEW you would use the Call Library Function Node. If you need help with that, please start a new thread and provide some documentation on the API.

[orchid]

Really is it like that? So, what is the purpose of the USB Raw? I have check at the device manager, and I see the NI-VISA USB Devices. What is that means? FYI, I am using Vista.

The vendor said that the API is a series of DLL. If is that so, I will start a new thread.

Thanks.