Not sure how much different the nevo software is than doing AMX or Crestron, but with them I have used:

for power on: ka 01 010x0D
for power off: ka 01 000x0D

Try not putting spaces between the 'k' and the 'a'. Also , put a zero before the set id number and the '0' or '1' for power, followed by a carriage return (0x0D in hex).