Modbus connect successful but fail for read_input_registers and read_holding_registers

[mintheinwin]

I am using the Calypso wind direction sensor from the product link provided below:
https://calypsoinstruments.com/shop/product/ultra-low-power-ultrasonic-wind-meter-ulp-standard-6#attr=76,71,65.

The device connected successfully, but reading the registers failed. The device contains 14 registers. What parameters should be passed for read_input_registers and read_holding_registers?

`#my full code.
import asyncio
from pymodbus.client.asynchronous.serial import AsyncModbusSerialClient
from pymodbus.framer.rtu_framer import ModbusRtuFramer
async def modbus_client_test():
# Initialize Modbus client
modbus_client = AsyncModbusSerialClient(
port='/dev/ttyS0',
framer=ModbusRtuFramer,
baudrate=38400,
stopbits=1,
bytesize=8,
parity='N',
timeout=1
)

# Use the client
async with modbus_client as client:
    if client.connected:
        print("Connection successful!")

        result = await client.read_holding_registers(address=1, count=1, slave=2)

        if not result.isError():
            print("Registers read successfully:", result.registers)
        else:
            print("Error reading registers:", result)
    else:
        print("Failed to connect!")

if name == "main":
asyncio.run(modbus_client_test())`

Error reading registers: Exception Response (131,3,None)

[janiversen]

As you can see in the log, your device does not respond.

That can be due to quite a number of communication parameters or slave= being wrong

That connect() succeeds only means pymodbus can open the port and set the communication parameters.

[janiversen]

Potentially it can also be your rs485 converter or the wiring.

[mintheinwin]

@janiversen Thanks for your reply.
How can I verify the device's communication parameters or ensure the slave configuration is correct?
Which third-party tools are easy to use for Modbus?
Calypso wind direction sensor Register number starting from 200.

[janiversen]

Read the manual, apart from that try and error.

What do you mean by third party tools ? search in google.

[mintheinwin]

I'm not familiar with Modbus. I mean third party software for test sensor with Modbus software.

[janiversen]

Not sure what you need, pymodbus offer REPL, please see the documentation.

This is the pymodbus project we generally do not speak about other projects or software.

[janiversen]

There are no indication this is a pymodbus problem, so closing.