Modbus communication error via USB connection

[ashnu57]

Hello,

I have  a Jumo ctron device that has a USB/TTL convertor to connect to PC. This is recognised as COM port in MAX. But when I try to test this connection via Visa test panel, I get the following error. 

The final application of this would be to control temperature (both i/p and o/p). 

I have attached the related documents regarding to the configuration of the Jumo cTron. Additionaly I have also attached the modbus interface description.

[CyGa]

Hi,

From what I've seen in the b70.....pdf, nowhere is written that your device understand *IDN? commands...

Also, the termination character is \0 and not \n as seen in the screenshot.

You should take a look at page 16 of the pdf, a lot of interesting things are written in it.

[ashnu57]

Thank you for the response.
I tried putting the simple command "01 03 0067 0002" in the command window by changing the termination character as well. I am getting the same error as before. I am not sure for the reason of not getting "Master-slave" connection.
As usual, if I click  query I get this error:VISA: (Hex 0xBFFF0015) Timeout before the process could be completed.

If I click on Read status bytes:
VISA: (Hex 0xBFFF003A) The operation could not be started because the settings are invalid (there is a conflict with the settings).

If I see in "View attributes": It says "Invalid property value"

I guess there is something really missing or not going well in the basic stuff itself. Please help me in finding the solution!

[ashnu57]

I tried to connect to the device via modbus in labview, the code looks in the way it is attached. I see a temperature value around 25 in read vi. Whereas in write vi it runs for a while and comes out with an error as shown. I need some suggestions in improving the code. I would like to write the temperature value in write vi to the controller.

The error is pointed towards the visa read connection. I'm not so familiar with this kind of coding. kindly help me

Thanks in advance

[CyGa]

Hi,

Are you trying to run Read and Write VIs simultaneously ?

Are you sure that you can write in the register pointed by the adress furnished to the Write VI ?

[ashnu57]

I tried running both vis together and individually, however I am unsure about this running procedure. But in both process I get the same error at write vi.

Regarding the address I am not sure about it. But I would like to explain how I considered the address

As per page number "13" of b70.2070.2.0gb (3) pdf. 
slave address: 01

Function code : 06

Word address: (here I want to write the temperature value to the controller) Initially I thought it must be binary controller:004D but later I think it also might be set point value i.e. 0050 or 3100
Holding register value: I am even not sure about this value

[ashnu57]

Hello,

I found the solution. I followed the procedure as per this link :  https://www.labviewforum.de/showthread.php?tid=24898

Thank you very much for your time and support.