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In the post you linked, you stated you got this working with an Arduino UNO. Is this true? If so, wouldn't the Arduino UNO and Arduino Nano be very similar, both hardware and software-wise, even using the same code? Did you try using the TX and RX pins with the ArduinoModbus library?

It appears that with the ArduinoModbus and ArduinoRS485 libraries, you must use the TX and RX pins on the Arduino. Even the RS485.setPins() function doesn't seem to allow you to change the TX and RX pins used for data transfer. Try using the TX (D1) and RX (DO) pins on the Arduino instead of D2...

Full disclaimer, I have no experience with the Arduino myself, just using Google here, but my guess would be to use this function: RS485.setPins() https://www.arduino.cc/reference/en/libraries/arduinors485/setpins/ Just to confirm, you are using an RS-485 shield, such as this one, right...

Take a look here for example code: https://github.com/arduino-libraries/ArduinoModbus/blob/master/examples/RTU/ModbusRTUClientKitchenSink/ModbusRTUClientKitchenSink.ino You want to focus on the setup() and readHoldingRegisterValues() functions. The input module you have gives you two options...

In the Radzio! Modbus Master Simulator there is a dropdown menu to select the type in the Device Settings section. You currently have Input Status selected, which results in the 02 function code. You need to select Holding Register for it to use the 03 function code. Also, the Address field...

The RS-485 and RS-422 standards are electrically similar, and it may even be possible to directly connect the RS-422 and RS-485 devices together for communications (otherwise you could use a RS-485 to RS-422 converter; here is one example...

What makes you believe the Ethernet (UDP) converter board uses CAN? Where do the RS-485 wires go that are connected to the acquisition modules? From the online documentation (https://en.kinco.cn/Download/D_enUserManual/HMI/Kinco%20DTools%20User%20Manual.pdf), it seems the Ethernet port of the...

OK, from your images, I see that the RS-485 Modbus RTU devices are these: https://www.aliexpress.us/item/2251832864773614.html https://www.infwin.com/flex3015-8-channel-thermistor-ntc-acquisition-module-rs485-modbus/ But what is the device/board that's converting this RS-485 Modbus RTU network...

Well the reason you're having trouble decoding Modbus RTU over UDP from these packets is probably because it's not Modbus RTU, or any other version of Modbus for that matter. Yes, it is UDP, and every packet is a broadcast. The UDP port used (4660) is a registered port with IANA and seems to be...

Could you just use Inkbird's WiFi enabled temperature controller instead of the ITC-1000F? https://inkbird.com/products/temperature-controller-itc-308-wifi Otherwise, perhaps one of these other options would work. https://smartpid.com/...

The master's timeout setting is for how long it will wait for the slave's response. When reading a single register, the difference is negligible (7-byte response packet so 7ms versus 3.5ms), but when reading a lot of registers, say 100, this is where the timeout setting becomes important...

Without being able to perform any testing to see what impacts the communication, it's going to be nearly impossible to determine exactly what is causing the communication problems. Typically when there are wiring/grounding/electrical issues, you see problems occurring the other way around - when...

Can you please provide details on what you have tried, including wiring, communication settings, software, etc.? While I'm not familiar with this particular device or protocol, I am fairly well versed in serial communication in general and may be able to help if you are able to describe exactly...

Just to confirm, when you say you're changing the baud rate, you're changing it on both devices, correct? What do you have the parity and number of stop bits set to for both devices? Make sure they match. It's possible that your wiring may be the issue. I recommend starting by making sure you...

Make sure you're trying to read the correct registers. To do this, you need to first understand what register notation both the Tricon and Modbus Doctor use. Refer to this post for the various notations: https://control.com/forums/threads/modbus-register-numbering.49844/ From your Modbus Doctor...

Can you please clarify what you mean by "continuous response"? Your communication log seems to show several TX packets in a row, indicating timeouts are occurring. How long is the master's timeout setting configured for? You may need to increase this value.

You need to make sure you are accessing the correct register number and selecting the proper data format. The register number for the Frequency register is 3110 (using 1-based numbering), but you are trying to access register 3109. This may be correct if the SOFREL S550 system uses 0-based...

There could be a lot of reasons why you're seeing what you're seeing. One possible reason, which is why I recommended using commercial software, is there may be a bug or mistake in your VB program. I just noticed this now, but it seems you're trying to access port 80. Port 80 is for HTTP. The...

I recommend trying a commercial Modbus master software tool such as ModScan, Simply Modbus, or Modbus Poll. Note, that some of these tools use 1-based Modbus register addressing, so you may need to add 1 to the register address (i.e. 769 instead of 768). What are the expected values of the...

Reading 2 registers in one request is one thing (and is supported by most every Modbus master), but interpreting those two registers as a single number is an entirely different matter (especially when you consider register/word ordering, integer vs. floating point, etc.). If the master is...