Re: Open a labview window to display GPIB data.
Do you have an NI GPIB board? If you do, you might want to check the installation of VISA software and even try doing a re-install. I'm not sure what the LeCroy software might be doing but another thing to try is to make sure it's closed and not running when working with MAX.
Re: Open a labview window to display GPIB data.
Hi Dennis, I'm sorry for all these questions. The clicking of the right VISA arrow doesn't give me any VISA resource names on my system. I did a scan with Max which tells me that I don't have any GPIB connection (which isn't the case), altough when I check on Scope Explorer it tells me that I'm connected to GPIB and gives me its address. Ninskaya
Re: Open a labview window to display GPIB data.
ScopeExplorer is not a scope. It is a program that communicates with LeCroy scopes. Go to LeCroy's web site for http://www.lecroy.com/tm/library/software/LabView/LabViewDrivers.asp?menuid=4";>LabVIEW Drivers or NI's Instrument Driver Network for http://search.ni.com/query.html?lk=1&col=alldocs&nh=500&rf=3&ql=&pw=595&qp=%2BContentType%3AInstrumentDriver+%2BIDNetManufacturer%3A%22LeCroy%22&qt=&layout=IDNet";>LeCroy and download the driver for your brand of hardware. If you have a choice, get a LabVIEW driver as opposed to an IVI driver. An IVI driver will work but it's a bit harder to setup and you won't be able to modify the program or even see the code unless you also have LabWindows/CVI. In either case, with the driver you won't have to do any VISA Reads yourself unless you feel like you want to recreate what has already been done for you. The http://www.ni.com/devzone/idnet/";>Instrument Driver Network main page has some links to definitions of the different types of instrument drivers and how they should be used.
Re: Open a labview window to display GPIB data.
Like I said in my answer to one of your other postings, you've got the wrong driver. The HP34401 is a DMM. You should be able to use the VISA Open from the Instrument I/O>VISA>VISA Advanced palette to open a connection to the instrument. If you create a VISA resource name control or constant you should be able to click on the little arrow on the right side to see a list of all valid VISA resource names on your system. This is assuming that you've had MAX do a scan for instruments. Do this by expanding the Devices and Interfaces listing in MAX, select the GPIB0 listing, and right click on it.
Re: Open a labview window to display GPIB data.
Thanks a lot. Ninskaya
Re: Open a labview window to display GPIB data.
You will be able to open up Measurment and Automation Explorer (MAX) to view all devices configured on your machine. You should be able to see what address it is under gpib devices.
Re: Open a labview window to display GPIB data.
Sorry, the scope is a Lecroy Scope Explorer version 2.12. Ninskaya
Re: Open a labview window to display GPIB data.
Hi Dennis Knutson, thanks a lot for your help. I am using ScopeExplorer as a scope. I am sorry, I don't really understand in which form the data will be. Shall I use the Read Visa vi like another person suggested and if yes how can I found out about the GPIB address? Thanks, Ninskaya
Re: Open a labview window to display GPIB data.
You don't mention the type of scope or whether you're using a driver but I'm going to assume that you are. Every driver that I've seen has a function to return the scope waveform. It may be as a 1D array or as a waveform datatype. In general, all you have to do is wire a graph to the returned data. Most drivers come with an example that do this already. Put this in a loop and you'll have continously updating data. There is no such thing as "real time". The max data transfer rate for GPIB is 1MB/sec and real world numbers are usually much less. From the number of samples you request from the scope, you should be able to determine the delay between the scope acquisition and the display on your computer. If you need more details, please provide the make and model of the scope that you're using.
