int16 on modbus script

[CristianAgata]

Hi everybody,
I've a problem on a script. I'm tring to read a solar inverter ZCSAzzurro. I've problem on negative number.
I've made this request:

if (res9[2] == nil) then
-- Chiamata potenza rete
  res10=nil
res10 = { mb:readregisters(530,dt.int16) }
  grp.update('Potenza_rete',(res10[1]))
log("Grind_power",res10)
  os.sleep(1.1)
  else
  --log("timeout!")
  mb:close()
end


But in the log I find the number 32767. But if try to make a read in the modbus scheduler I get -27 (right value)
Where am I wronging?

Thanks for who will help me.

BR Cristian