222.100 datatype on 6 bytes

[Erwin van der Zwart]

Hi,

Create a 255 byte object (1/1/1 in this sample) and link it to the address of your 6 byte value that you use in the ETS and attached this script to it:

Code:

if event.src ~= 'local' then
 value = event.getvalue()
 value = lmcore.strtohex(value)
 bytestable = {}
 for i = 2, #value, 2 do
   bytevalue = string.sub(value, (i-1), i)
   table.insert(bytestable, bytevalue)
 end
 value1 = knxdatatype.decode(bytestable[1] .. bytestable[2], dt.float16)
 value2 = knxdatatype.decode(bytestable[3] .. bytestable[4], dt.float16)
 value3 = knxdatatype.decode(bytestable[5] .. bytestable[6], dt.float16)
 grp.update('32/1/1', value1)
 grp.update('32/1/2', value2)
 grp.update('32/1/3', value3)
end

That will give you the 3x 2 byte float objects that you can export to BACnet.

Attach a tag to the 3x 2 byte float objects and create a event based script attached to that tag and paste this script in it:

Code:

if event.src == 'local' then
  value1 = grp.find('32/1/1').datahex
  value2 = grp.find('32/1/2').datahex
  value3 = grp.find('32/1/3').datahex
  sixbytevaluestring = lmcore.hextostr(value1 .. value2 .. value3)
  oldvalue = grp.getvalue('1/1/1')
  if oldvalue ~= sixbytevaluestring then
    grp.write('1/1/1', sixbytevaluestring)
  end
end

This will write the (BACnet side) changed value back to your 6 byte object. Because i added event.src you can use the same 255 byte object for incomming and outgoing telegrams and avoid triggering a loop.

BR,

Erwin