ISO MME Data Set Issues

[DIAdemon]

We are experiencing some difficulties/awkwardness with the DIAdem MME data import function. Please consider the following:

1. The keywords from the channel file are stored in a vector (MME_ChnInfoDesc) and the related values are stored in a matrix (MME_ChnInfo). This scheme assumes the keywords are in the same order in all channel files that comprise the MME set. This is not the case as the ISO specification allows comment keywords to “be used at any line”. In addition, many of the keywords defined in the ISO specification are optional. The insertion of optional keywords will result in channel files with differing keywords and the MME_ChnInfoDesc vector will not represent the keywords properly.
2. Is it possible to have the MME reader only load specific channels in the MME data set, rather than loading the entire MME data set? We have very large MME sets from which only a few channels are required. We do not want to allocate time or memory to handle the excess data.
3. There are no provisions to retrieve the comments for a particular channel from the channel comment file (CHANNEL.TXT).
4. There are no provisions to write MME data channels, sets, or comments.

These issues are forcing us to consider writing a low-level driver to read and write MME data. Does NI have any advise for us on this issue?

Thank you very much.

[Caroline Bright]

Hello,

It sounds as if you are using the MME import based on the DIAdem GPI extension "gfsmme.dll". There is currently a new DataPlugin for ISO-MME on our website that has more functionality. YOu can find this at http://www.ni.com/dataplugins.htm. The older GPI import used variables while the new plugin stores the MME parameters in groups and channel properties. The new DataPlugin will be much more useful to you but you may have to adapt your application to access these MME properties. As to each of your questions:

1. The DataPlugin does not require a fixed order of keywords in the channel files. This was an issue however with the GPI import.

2. The plugin in capable of loading specific channels as well as registering large sets of data.

3. THe channel comment file is optional in the MME format without and format requirements. This plugin does not by default access this file butyou could customize the script to do so.

4. Currently, we still do not have these provisions in the plugin but I will make a product suggestion for it to be included in the future.

Thanks,
Caroline
National Instruments.

[DIAdemon]

Thanks for the feedback.

It appears to me that the DataPlugIn's are designed to work when data sets are opened manually through DIAdem navagator. They do not apparently execute when we load data sets through scripts created and executed under DIAdem Scripts? Do I understand this correctly?

[Brad_Turpin]

Hi DIAdemon,

Quite the contrary! Of course, DataPlugins and the functions to load data with them that I describe below are all features of DIAdem 9.1 and above, but here's the scoop.

Call DataFileLoad(DataFilename, [FileImportFilter], [ImportAction])

... will load the entire data set (DataFilename) using the DataPlugin (FileImportFilter), either fully loaded or file-registered (ImportAction).

Call DataFileLoadSel(DataFilename, FileImportFilter, ImportSelection, [ImportAction])

... will load as above except that you can specify a subset of channels (ImportSelection) to load from the data set. You can use the same [Group]/[Channel] syntax that you have in VIEW and REPORT layouts to specify which channels you want, and you can even use some limited wildcards.

For the truly stout of heart, you can also use the "Ods..." commands in DIAdem to execute property queries on the DataPlugin data set for even fancier selective channel loading.

All this is available programmatically,
Brad Turpin
DIAdem Product Support Engineer
National Instruments

[DIAdemon]

Thanks for the plug in info. We had a couple more questions regarding NI's MME support.

We know the ISO committee is about to announce modification to the specification where the data sets support more than 999 channels. Later in the year, the committee intends release a version based on XML. Our questions are:

1. Does NI intend to incorporate these specification modifications into future versions of DIAdem?

2. When the modifications are released and start being implemented, the customer base will have to live with several formats. If NI supports the evolving specification, will the DIAdem interface be backward-compatible?

Thank you very much.

[Caroline Bright]

Hello DIAdemon,

To answer your questions:

1.) The ISO committee regulary update the related electronic documents (RED) of the MME norm. It is planed to add hints how to deal with more then 999 channels in the oncomming RED version 1.4.
The ISO has adopt a working proposal for a new standard VSIM (Vehicle Safety Information Model) which will contain data exchange based on XML and based on ASAM-ODS. The VSIM standard proposal is in work. It is not planned by the working groups to append the MME standard to a XML based data exchange.

2.) Yes, we plan to incorporate specification modifications of MME into future versions of DIAdem.
There are currently no plans for VSIM, which may be an ISO standard in two years. VSIM will be based on ASAM-ODS which is already supported by DIAdem.


3.) We have various import filters to deal with different ISO standards and versions of them.

Thanks,
Caroline
National Instruments