def read_input_registers(slave_id, starting_address, quantity):
""" Return ADU for Modbus function code 04: Read Input Registers.
:param slave_id: Number of slave.
:return: Byte array with ADU.
"""
function = ReadInputRegisters()
function.starting_address = starting_address
function.quantity = quantity
return _create_request_adu(slave_id, function.request_pdu)
def read_input_registers():
instance = ReadInputRegisters()
instance.starting_address = 50
instance.quantity = 2
return instance