import asyncio
from pymodbus.server import StartAsyncTcpServer
from pymodbus.datastore import ModbusSlaveContext, ModbusServerContext
from pymodbus.datastore.store import ModbusSequentialDataBlock

# 建立 HR 暫存區，從位址 1633 開始，總共 100 筆
store = ModbusSlaveContext(
    hr=ModbusSequentialDataBlock(1633, [0]*100)
)
context = ModbusServerContext(slaves={255: store}, single=False)

async def read_loop():
    while True:
        # 從 HR address 1633 開始，讀取 3 筆資料
        values = context[255].getValues(3, 1633, count=3)
        print(f"PLC 寫入的資料: {values}")
        await asyncio.sleep(1)  # 每秒顯示一次

async def run_server():
    asyncio.create_task(read_loop())  # 啟動背景讀取任務
    await StartAsyncTcpServer(context, address=("169.254.11.130", 502))
    

if __name__ == "__main__":
    asyncio.run(run_server())