Can I obtain tag data from an Industrial PLC w/o OPC servers?

[adavies78]

I'm running LV2009 F3 with the DSC module and OPC servers to do development.  This question pertains to deploying an .exe to a target machine.

I built a data-acquisiton system for my company's factory to generate spatial maps of various parameters during the in-line processing of our product.  My application is pretty simple, in that it just acquires voltages, processes the data and generates a brief report.  But the report is only useful if we can track it to the part# for each unit.

There is a barcode reader nearby, which reports data to an AB ControlLogix5561 PLC, and I'd like to be able to access the data in the Barcode_Read tag.

I have done this with intermittent success now twice.

     -the first time, i couldn't get the device address figured out in NI OPC Servers, so i set up an OPC server using RSLinx Classic, and then made a shared variable to bring that data into my application.  It turned out I was using an evaluation version of RSLinx, which expired right as soon as I found and fixed that i needed the run-time license to deploy my DSC-ready app to a target machine.

     -Instead of paying Rockwell the extra $1k for an RSLinx license, I had another go at using NI OPC servers and managed to find the right syntax (actually the right help file that *showed* me the right syntax) for the device address.  Got it working again right away on my development machine.  Now, comically, when I installed the DSC-RTS on the target computer, it also installed an evaluation version of OPC Servers, so my app worked again just long enough for me to push it out of my head before that one expired too.

     -Instead of paying NI the extra $1k for another OPC servers license, i thought i'd ask this group if anyone knows if I can do this directly in my VI, instead of setting up an I/O server in the Project.  it *looks* like I should be able to do this, using the "create I/O server" express vi on the engine control pallete to generate a root URL, then making a tag reader from there to read the tag data from the PLC.  But has anyone done it?  Does this acheive the same result as configuring the channel/device in OPC servers, and the dropping shared variables for the tags into my vi?

Thanks in advance!

[tomlawton]

Hi-

check out Mango M2M. Can't promise anything for your protocol, but it gave me a free, OPC-free, way to access BACnet. Mango grabs tags (from all sorts of sources) and publishes them on a webpage. Scrape the html in LabVIEW... job done 😉

Mango's support (one guy, the author), is awesome.

HTH

Tom

[Labview_expert]

If you are phasing any promblem related BACnet protocol. Dont buy any opc server.I have developed Small BACnet protocol communication toolkit in the labview.

Using this toolkit you upload your BACnet data into NI opc also.