Python • Syntax error: positional argument follows keyword argument pymodbus

Hi, I have installed Raspberry Pi OS (64-bit) on my 4b. I installed Python3-pymodbus-3.00-7 using the "Add/Remove Software" GUI. I am trying to build a Modbus TCP server. I copied this code into Thonny, and it is throwing a "Syntax error: positional argument follows keyword argument". I don't understand why sample code has a syntax error in it?

from pymodbus3.server import StartTcpServer
from pymodbus3.datastore import ModbusServerContext, ModbusSequentialDataBlock, ModbusSlaveContext

# Define a simple data block with 10 registers
store = ModbusSlaveContext(
di = ModbusSequentialDataBlock(0, [0x0]*10000),
co = ModbusSequentialDataBlock(0, [0x0]*10000),
hr = ModbusSequentialDataBlock(0, [0x0]*10000),
ir = ModbusSequentialDataBlock(0, [0x0]*10000))
context = ModbusServerContext(slaves=store, single=True)

# Start the Modbus TCP server
# Change parameters to your host and port
server = StartTcpServer(context=context, address("0.0.0.0", 502))
print("Modbus server started")
server.serve_forever()

Statistics: Posted by RyCar66 — Tue Mar 04, 2025 1:44 pm

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