pymodbus_sync_tcp_client_read_holding_registers.py

1import logging
2from pymodbus.client import ModbusTcpClient
3
4# Configure logging
5logging.basicConfig()
6log = logging.getLogger()
7log.setLevel(logging.INFO)
8
9def run_sync_client():
10    # Define client connection parameters
11    # For a local simulator, the default port is often 502 or 5020
12    client = ModbusTcpClient('localhost', port=5020)
13    
14    # Connect to the server
15    connection = client.connect()
16    if connection:
17        log.info("Connected to Modbus Server")
18        
19        # Read 10 holding registers starting at address 1
20        # slave=1 specifies the unit/slave ID
21        result = client.read_holding_registers(address=1, count=10, slave=1)
22        
23        if not result.isError():
24            print(f"Register values: {result.registers}")
25        else:
26            print(f"Error reading registers: {result}")
27            
28        # Close the connection
29        client.close()
30    else:
31        log.error("Failed to connect to Modbus Server")
32
33if __name__ == "__main__":
34    run_sync_client()