How to read data from OM-62 temperature/humidity data logger in LabVIEW?

[Zac58]

Hello,

I have an Omega OM-62 temperature/humidity data logger that I want to communicate (initialize recording, read/write data, end recording) through LabVIEW 8.6. The OM-62 is connected to the PC via a USB-miniUSB type B connector, and I have the supplied "Omega Interface Logger Program" on my Windows operating system. I've called Omega's DAQ help-line but was told that low-level data loggers like this do not have supplied LabVIEW capabilities which I completely understand.

My question is why do I have to use their program to communicate to this device? If I knew the syntax their program used to communicate to the device, why can't I use that through VISA? Do I need to build my own LabVIEW driver from their supplied driver?

Is Python a more applicable solution for this scenario?

How could I view the code "Omega Interface Logger Progam" uses on my Windows operating system to communicate to the OM-62 sensor?

I just would like to know how this could or couldn't work as I feel I am missing some concept in my novice LabVIEW/programming understanding. It would be easier to run both my LabVIEW program and their program at the same time, but I just want to understand this at a deeper level.

Curosity Killed the Non-computer engineer,

Zach

P.S. I have attached some driver set-up information, but I have no idea if this is helpful.

[nyc_(is_out_of_here)]

Frankly I am not in the mood to do your job for you.

Read their manual and tell us what it says about connectivity to 3rd-party software other than their own.

[Zac58]

nyc,

The manual doesn't say anything about 3rd party connectivity and as I mentioned before the help-line's response was that there was currently none through LabVIEW. I only supplied the manual as supplementary information to those that were in "the mood" to gather more detail about the device than I thought necessary to fill up the whole space of my post. My questions pertain to general concepts about LabVIEW and communications and not anything that is availble in the manual.

And frankly, I don't need your help if your gonna be in a mood.

-Zach

[Dennis_Knutson]

Why do you think python is going to help you understand the low level usb communication when LabVIEW can't? What sort of sniffer program have you run? Have you asked omega for the usb raw protocol? Do you know what sort of usb class that the instrument uses? Most of your problems are related to not understanding usb and not LabVIEW.

[Dennis_Knutson]

http://forums.ni.com/t5/LabVIEW/Nugget-1-of-n-GEtting-started-with-USB-communication-via-VISA/m-p/74...

This should serve as a starting point about usb.

[Zac58]

Dennis,

You are completely right; I don't understand. I just wanted someone to point in a general direction so I could research more about it. I will gladly take your suggestions and hopefully return with better questions.

Thank you for your quick reply and constructive critisicm,

-Zach 

[mikerophone]

Zac58,

In general, communication with third party devices in LabVIEW is a little less straightforward compared to other types of communication protocols like serial or GPIB since different USB devices can vary widely in the command sets used to address them.  Though these are not comprehensive about USB communication in general, here are a few articles on our website that outline how to use NI-VISA with USB instruments.  Hope this helps!

http://www.ni.com/white-paper/4478/en/

http://digital.ni.com/public.nsf/allkb/E3A2C4FE42D7ED0D86256DB7005C65C9

[Zac58]

Thanks mikerophone, this seems like great reading material.

[Sam_Sharp · Accepted solution]

Unless the manufacturer provides some sort of programming interface or API for communicating with the device you're going to have a hard time interfacing to it with your own software be it LabVIEW or Python or anything else. That could be in the form of a driver dll, serial protocol, modbus (etc. etc. etc.).

If that isn't provided/available and you really need to communicate with the device you would need to look at using something like a USB/driver sniffer (software? hardware?) to try and intercept the communications between their software and the device. You can then use this information to try and figure out what commands it sends and the response received and how to convert that into the data.

Once you've got that far...I'm not sure what options LabVIEW has for low-level USB device control but at a guess I'd say you'd need either a low-level USB driver or you'd need to write your own driver in another language and then call that from LabVIEW.

[Zac58]

Dennis,

Omega will not disclose their raw USB protocol. I am having trouble finding a USB sniffer program. I know you have offered "Portmon" in previous posts but I have read that this program cannot work with my windows 7 64bit OS.

What USB sniffer programs would you recommend, either free or relatively cheap?

-Zach