This is kind of a mess. None of the wires in the panel are labeled, although it looks like it was constructed well enough.
You need a wiring diagram for this thing to answer your questions. You also need to figure out what's on the other end of the device cables and what color is connected to what.
Can you get any information from the original manufacturer? Or was that the seller? Did the seller take any pictures before it was disassembled?
The V120 has the ability to send and receive text messages, which is what the cellular modem is for. It's not really "internet capable".
It may be possible to determine the functionality of the system by uploading the program from the V120 an analyzing it.
Update - the newest release of UniLogic offers a "SHAPE Line" data type which is called from the ladder program. These functions are in the new "Drawing" menu at the bottom of the Toolbox. The Help says that these are not yet documented and I don't know how it works yet, but maybe one of the Creators can chime in and give us some direction.
@Cara Bereck Levy - anything on this?
You're probably going to have to swap the words on anything you read in 32 bit land. Look at this post on how to do that-
I'm guessing you meant 82.
If you're going to get deep into troubleshooting Modbus then you need to browse this document, which is the original Modbus protocol description:
Starting on page 22 you'll see the function code descriptions.
First off, looking at your transmission block, using 1X is just bad form unless the device's modbus table description specifically calls them "inputs". Reading inputs is code 02, reading coils is code 01.
Look at this page:
If you send a Modbus command and the slave chokes on it, it returns the command with the error bit which corresponds to hex "80". So "02" incorrectly sent becomes "82".
You also have 3X embedded in your requests, which shouldn't work either. They should be 4X for holding registers. 3X is for input registers, and it's not common to use these anymore.
If 1X and 3X work in devices on your Indusoft Modbus configuration then it means the creators of the devices probably put code in to accept either command or they really truly designed the devices to the old Modicon PLC specification, where 1X were discrete input modules and 3X were analog input modules.
I'm getting close to going on a rant so I'll just leave it at that. In summary you should really only be using 0X and 4X in your Modbus table.
And yes, we have done Web Studio projects. It used to be a really cost-effective platform before Wonderware "Software that's Fun-to-Wear" bought them out and doubled all the license prices.