VI LOGGER writing variables to VI Logger from labview / and logging PLC data through OPC ?

[Impossible_Possibilities]

I'm working on an integrated high speed DAQ Logging System (20k Points per second).

I'm happy with VI Logger for logging except that I can't figure out the following:

1. At run time I'm provided hardware information of the UUT from third party SW. This information needs to be used as a constant in VI Logger calculated channels. Is there a way I can write a value from within Labview to a MAX Virtual Channel or a VI Logger constant? An answer to this should alleviate my second problem.

2. Can I connect OPC PLC channels directly into MAX so I can log them to VI Logger? Is there another way(without using DSC)?

Thanks for any help you can provide.

[aasenjo]

There have been several requests for an interface in the Measurement & Automation Explorer (MAX 2.2) that would allow LabVIEW (or other applications) to create and modify virtual channels, scales or logging tasks.

This common interface (the functionality) does not currently exist but the suggestion has been taken into account by our R&D department for future releases of MAX.

For now, I recommend porting (part of) the calculations made on the acquired data to LabVIEW (if possible, it depends on the architecture of your application) instead of doing it from Virtual Logger.

The current version of VI Logger (1.0.1) can only log data from Virtual Channels. These Virtual Channels are the same ones used by the DAQ OPC Server to publish DAQ measurements usin
g OPC. Unfortunately it does not work the other way around (not yet anyway); Virtual Channels cannot be created using OPC devices because MAX does not have an OPC interface.This operation would be performed (as you note on your question) by LabVIEW DSC, which would allow you to connect to your OPC servers and log the data.

Regards

Alejandro Asenjo

Applications Engineer
National Instruments