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If I understand correctly, you're designing the entire system (both the client and servers), and all servers leave the production line with the same fixed device address (say address 1 for example). To my knowledge, there is no common approach to automatically set device addresses of Modbus...

Looking at your code, your problem wasn't that the text boxes were reversed. You're still reading the wrong registers. I mentioned this back in post #52. That's also why I stated the qualifier, "Assuming you are reading the right registers from the device (using...

Unless you have more experience programming in C#, I recommend that you keep using VB.NET. While there are advantages of using a more advanced language like C#, C# (like VB.NET) is also not designed for low-level data manipulation. The data conversion code is correct and is working properly...

This post details a similar issue as you've run into: https://bytes.com/topic/visual-basic-net/answers/349731-integer-byte It seems that Visual Basic performs overflow checking by default. This is why you are seeing the overflow exception. Visual Basic is not really intended for low-level data...

Thank you for the detailed connection description, however, you are still missing a common GND connection between the Arduino, MAX485, and the inverter. GND --- GND ARDUINO --- GND INVERTER Without wiring a common ground connection between all devices, you may see intermittent communication...

I encourage you to confirm the exact cause of why it was not working previously. Without knowing what caused the failure, you cannot be sure that you've fixed it. It is likely that you will have the same issue again, unless you identify the cause and confirm that your solution resolves the...

You're getting a NullReferenceException: Object reference not set to an instance of an object. This means that one of the variables you're trying to access is Null (i.e. uninitialized). There are several issues with the following 3 lines of your code Dim Registers As Integer() Registers(0) =...

To add to my previous response, the as SByte pseudo-code for casting to a SByte is also not proper Visual Basic syntax. I think you may need to use one of the type conversion functions here...

As I mentioned, I do not know Visual Basic, so the code example I provided you is NOT Visual Basic, but rather pseudo-code. You will need to translate my pseudo-code into proper Visual Basic code. The Microsoft documentation here will help you do this: Bit Shift Operators (Left Shift, Right...

There is a small issue with the pseudo code example I gave you, I did not sign-extend bits 23...16 of the 32-bit register value. The code should be as follows (note the addition of the "as SByte" cast): SByte exponent Integer mantissa Single value exponent = Registers[1] RightShiftBy 8...

You do have successful communications, but from your Wireshark captures, it appears that the EasyModbusTCP library uses 0-based addressing instead of 1-based. Therefore you need to subtract 1 from the register number, to read Input Registers 142 -143 (i.e. 30142 - 30143)...

Again, you're incorrectly trying to access the registers as Holding Registers when you need to access them as Input Registers. The 30,000 offset means they are Input Registers. Therefore you need to change ModbusClient.ReadHoldingRegisters to ModbusClient.ReadInputRegisters However, this is...

I'm confused about what you did to get it to work. Please clarify so that others reading this that may have the same issue have a clear understanding of what you did wrong (and what they may be doing wrong on their own setup). What's the difference between this: And this: Could you please...

I believe the method you're attempting to use is for special OLE controls that use the DLL or OCX extension and are special controls that implement the entry point methods DllRegisterServer and DllUnregisterServer functions. https://en.wikipedia.org/wiki/Object_Linking_and_Embedding...

Unzip the "Easy Modbus library for .NET(DLL)" and include EasyModbus.dll as a reference in your .NET project.

OK. This is different from the 0xE0 error you were originally getting. A timeout error is typically caused by one of two things (assuming hardware has not been damaged): wiring or configuration settings. Please triple-check that you have your RS-485 +, -, and GND connections correct and the...

Thank you for the additional information. You should be able to achieve successful communications with this setup. Are you receiving an error when doing this? If so, what error? If not, what makes you believe communications is not successful? Please detail what you mean by, "There was no...

As a general troubleshooting recommendation, only change one thing at a time and test the results. When you change multiple things at once, it's impossible to know what effect each change had on the system. OK, did you set S1:1 and S1:2 both to the OFF position on the inverter, as instructed...

Yes, you need to download one of the .NET Modbus libraries to your computer and include the DLL as a reference in your .NET project (note that the library may be offered in source code format instead, in which case you will need to compile the project into a DLL yourself or simply inclulde the...

You have your 470 ohm resistors connected incorrectly. Your schematic shows one resistor between B and VCC and the other between A and GND. Please review my previous instructions: Regarding your comment on S1 and S2: I don't understand why you need a response from ABB support. Don't you have...