Creating VI for Extech RH520 Temp & Humidity

[CDuck]

Hi guys I'm trying to create a VI to extract the temperature and humidity from the Extech RH520.

My knowledge is below CLAD any help and pointers would be appreciated

I attached a file that has the Hex language from Extech to PC COM port communications.  The COM port read a total of 761 time/temps.

[CDuck]

I think the attached file is for Serial Port Monitor only.  Let me know if you need me to post any of the Hex characters from the file

[CDuck]

I attached my Snippet Code, I can currently get it to work, but I would need to run a mouse recorder to constantly download the entire data base once every hour (using the very limited VI that RH520 has offered with their product.)

I'm hoping to get a VISA developed to communicate directly, I'm not sure how to request the information from the RH520 directly through my labVIEW program.  Should I call Extech to ask for the communication protocol?

[patrick.o]

CDuck,

I couldn't find any command protocols looking through the manual for the device on the manufacturer's website. You should call the manufacturer and ask for the command protocols.

Once you have the protocol, you can download NI VISA and try communicating with the device in LabVIEW using the coding example in the following article:

NI VISA Overview

http://www.ni.com/tutorial/3702/en/

I hope this helps.

[CDuck]

Ok so I got some of the data base to spit out onto the "read buffer" indicator.  Although it spit out the data, it also spit out this error shown in the attached picture.  Any ideas?

[CDuck]

Programming the RH520 requires the following:

1. Connect to the RH520 serial at 57600 baud rate, 8 data bits, 1 stop bit, no parity, no flow control (DTR is asserted at start by default with no flow in LabVIEW)
2. De-assert the DTR line in code
3. Wait 1000 ms
4. Assert the DTR line
5. RH520 will begin dumping data

[CDuck]

Here's where I am at now:

I figured out what they meant by DTR states.

It is workly slightly better, but still not a success. 

*There is about 1000 lines with a date on each in the data base*

However  it only grabs about the first 100 date lines, then grabs the first 100 again.  Once in a while it will continue past the 100 naerly to the current date.  -_-

I tried rearranging the Assert-Unassert-Assert combination with no luck, and not much difference.  Actually I think when I changed it it would be more succesful, but only for 1 run.

The error is almost always Read VISA timeout

Any Ideas?

[CDuck · Accepted solution]

SOLVED

The block diagram picture attached will allow you to dump the entire RH520 data base into a single string.  With a separate VI, You can then use this  string to search/split and filter the desired date you want from the front panel input. 

I did switch to LabVIEW NXG today and didn't feel like recreating the diagram in Classic LabVIEW.  However this can all be recreated with the same icons in either version of LabVIEW.

Also I would like to add that my knowledge is no longer below CLAD.. I passed the test yesterday!! 

I'll update this thread later to contain my string splitter later on (To pick a single date of data)

Enjoy!