Modbus, getting bits in a register

[Erwin van der Zwart]

Hi,


If you read a 16 bits integer register you can get back value 0 to 65535, but when this register is used as single bit (not coil) you probably get back only value 0 or 1 out of this register.

To use that value for a 1 bit KNX value you can simply transfer it to boolean by using this:

Code:

value = mb:readregisters(123)
if value == 0 or value == 1 then
 value = toboolean(value)
 grp.write('1/1/1', value)
end

To set 16 bits register value to 2 byte signed you can use this code:

Code:

r1 = mb:readregisters(124)
value = lmcore.inttohex(r1, 2)
value = knxdatatype.decode(value, dt.int16)

BR,
Erwin