Quantcast
Channel: Instrument Control (GPIB, Serial, VISA, IVI) topics
Viewing all articles
Browse latest Browse all 5625

Watlow PM with Modbus TCP

$
0
0

Hi community,

 

I have a watlow pm temperature controller connected to my computer with an ethernet cable. I need to communicate with the device via modbus tcp. I know for sure that the unit is functioning as if I use a modbustcp test program (see the first attachement), then I can read the temperature of the K type thermocouple which is connected to the unit. (the IP is 192.168.10.3, and I read two words from address 360). The temperature on the screenshot is 23.61992C

 

I would like to do this from LabVIEW by using an IO server. My problem starts at the beginning. I right click on my computer >> new >> I/O server >> Modbus

then in the popup window I select "Modbus ethernet" in the top right corner. I have attached this popup window. What is the Address in the communication settings section. The IP need to be entered at the bottom, so I have no clue what is the Address field is referring to.

 

Then I try to create bound variables... I see a huge list of registers, but honestly I dont understand how the address 360 I use in the standalone program translates to this list. Which one should I select from the list? Whatever I select gives me either 0 or FALSE if its a boolean. According to the documentation 360 is the relative address and the absolute is 400361. Actually there are a register list from 400001-465535, but if I select 400361-400362 I still read zero.

 

Reading only zeros and FALSE values... thats suspicious. Something is wrong.

 

Please help out with your thought! 


Viewing all articles
Browse latest Browse all 5625

Trending Articles