Modbus Communication to CrIO 9074 Target

[Ricardogfx]

Hi,

I created a project with a cRio 9074 and I want to read and write over my variables, since this program will be monitored and managed on the cloud. For this we chosed Modbus serial communication.  To try to do tests I connected my cRio directly to my computer with a RS232 to usb cable and used ModbusPoll to simulate a Master ,but when I try to connect with the ModbusPOll it gives me a timeout error.

On my labview project the only thing I did is add a Modbus Slave Server  with two boolean outputs.  With this configuration:

And on my modbus Poll the following config;

I'm new to Modbus communication and also Im a beginner on Labview, I know labview has its palette for modbus communication, so I dont know if i need to make a VI to open the communication. I'm not sure it that's needed because when I use labview as Master I have no problems communicating to the slave, I did a test using Labview as master and I could read and write to my target without any problem, using modbus ethernet, like this : 

I would appreaciate if someone can help me out.

Thanks.

[fernando.becerra]

Hello Ricardogfx, 

I recommend that you check out the examples on Modbus communication included in the LabVIEW Example Finder, which you can access from the LabVIEW Windows > Help Menu > Find Examples...

You should see a windows like this:

Click the search tab and write modbus and open the Modbus Library.lvproj.