Modbus, getting bits in a register

[Simuzer]

You can use this helper function:

Code:

function getbit(value, nr)
  value = bit.rshift(value, nr)
  return bit.band(value, 1)
end

value = mb:readregisters(123)
if value then
  dampers_open = getbit(value, 0)
  fire_dampers_open = getbit(value, 1)
  ...
end

Its work for read any bit of 16bit register.

i also write any bit of 16bit register this like..

Code:

function updatebit(bit_value, ModbusAddress, bit_no)
  ????
  ????
  ????
end

For example;

Code:

 updatebit (true, 123, 0)
 updatebit (false, 123, 5)

1. --
before modbus 123 register: 1010 1101 0110 1011 (=44.395)
after modbus 123 register: 1010 1101 0110 1010 (=44.394)
2.--
before modbus 123 register: 1010 1101 0110 1010 (=44.394)
after modbus 123 register: 1010 1101 0100 1010 (=44.362)