from pymodbus.client.sync import ModbusTcpClient as ModbusClient
from pymodbus.exceptions import ModbusIOException
from time import sleep


client = ModbusClient('172.16.2.157')

try:
    client.connect()

    processImage = client.read_holding_registers(0x1010, 4)
    if isinstance(processImage, ModbusIOException):
        raise Exception(processImage)

    if len(processImage.registers) != 4:
        raise Exception("Unexpected number of registers in process image ({})".format(len(processImage.registers)))

    (analogOutputBits, analogInputBits, digitalOutputBits, digitalInputBits) = processImage.registers
    print(f"AO: {analogOutputBits}, AI: {analogInputBits}, DO: {digitalOutputBits}, DI: {digitalInputBits}")

    while True:
        reg = client.read_input_registers(0, analogInputBits // 8)
        if isinstance(reg, ModbusIOException):
            raise Exception(reg)
        print(reg.registers)

        reg = client.read_discrete_inputs(0, digitalInputBits)
        if isinstance(reg, ModbusIOException):
            raise Exception(reg)
        print(reg.bits)

        reg = client.read_coils(0, digitalOutputBits)
        if isinstance(reg, ModbusIOException):
            raise Exception(reg)
        print(reg.bits)

        sleep(0.1)

except Exception as e:
    print("Exception: {}".format(e))
finally:
    client.close()