How to continously recorded the iput and output wave

[sonic]

Now i used the NI-FGEN and NI-Scope for Bender element test,my question is how to save waveform (input and output wave) for every 10 sec (during cyclic triaxial test), thanks you for your kind"

[AndrewM]

Hello,

The answer just depends on how you are acquiring your data. I am assuming that you are acquiring and generating your data within some sort of looping structure. If that is the case, then you should be able to take the data you are collecting and generating and create a binary file that would store that information. There are a number of examples showing how to log data in LabVIEW. What you would want to do is to create the binary file outside of the loop and then write the data at a specific interval and then close the file outside of the loop.

For information on logging data, please refer to Find Examples under the Help menu in LabVIEW.

Regards,

Andrew M
National Instruments

[DFGray]

We created a fast binary format specifically for this type of application. It ships with NI-SCOPE and NI-FGEN. Early versions of it are found on your installation CD. Look for the sfpFile directory. A much easier-to-use version is included and installed with the latest NI-SCOPE. It is called NI-HWS. The file format is identical with both products, but the API is very different. Both include examples of use. This is the default file format used by the NI-SCOPE and NI-FGEN soft front panels.

If you have any problems, let us know.

VERY IMPORTANT NOTE: Both APIs are based on HDF5. HDF5 is not multi-thread safe under Windows. The NI-HWS API provides some protection. sfpFile does not. You must ensure that any access to the subroutines is done serially.

[sonic]

Thank you so much for your advice,I used NI-scope software Ver. 2.1.4 and NI-FGEN Ver. 1.6 anyway I cannot find the NI-HWS could you tell me more detail about this. Thank you for your kind.

[DFGray]

I did a bit more looking and found out that I was wrong. My apologies. NI-HWS is currently shipping with the high-speed digital products and the waveform editors (analog and digital). It is not shipping with NI-FGEN or NI-SCOPE. sfpFile shipped with NI-SCOPE 2.1.2 through 2.5 and NI-FGEN 1.5. NI-HWS was not finished in time for the latest NI-SCOPE and NI-FGEN releases. For now, you will need to use sfpFile. Copy the examples to make your life much easier. Your application is simple enough that the basic functions should work for you. Don't worry about losing your data, since sfpFile and NI-HWS use the same format. In any case, it is all based on HDF5, and you can get HDF5 utilities (free for any use) from the NCSA website. A word of warning - HDF5 is VERY powerful, but also VERY difficult to use. sfpFile and NI-HWS are based on the 1.4.4 release of HDF5. The current 1.6.x release of HDF5 is file format compatible, but binary incompatible with the 1.4.x release. NCSA did not change the format of the files they are writing, but did change the code that writes to them.