python-snap7

import snap7 from snap7.snap7types import S7AreaDB import os # Configure PLC connection details plc_ip = os.environ.get('PLC_IP', '192.168.0.100') # Placeholder IP plc_rack = int(os.environ.get('PLC_RACK', '0')) plc_slot = int(os.environ.get('PLC_SLOT', '1')) client = snap7.client.Client() try: client.connect(plc_ip, plc_rack, plc_slot) if client.get_connected(): print(f"Successfully connected to PLC at {plc_ip}") # Example: Read 10 bytes from Data Block (DB) number 10, starting at byte 0 db_number = 10 start_byte = 0 size = 10 data_buffer = client.db_read(db_number, start_byte, size) print(f"Read from DB{db_number}, Start:{start_byte}, Size:{size}: {data_buffer}") # Example: Write 10 bytes to Data Block (DB) number 10, starting at byte 0 # Make sure the PLC is configured to allow writes. # new_data = bytearray([0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A]) # client.db_write(db_number, start_byte, new_data) # print(f"Wrote to DB{db_number}, Start:{start_byte}, Size:{size}: {new_data}") else: print("Failed to connect to PLC.") except Exception as e: print(f"An error occurred: {e}") finally: if client.get_connected(): client.disconnect() print("Disconnected from PLC.")