require "rmodbus"
require "ccutrer-serialport"

mode = ARGV[0].strip
controller_id = ARGV[1].to_i
value = ARGV[2].to_i

ModBus::RTUClient.new("/dev/ttyUSB0", 9600) do |cl|
  cl.with_slave(controller_id) do |slave|
    regs = slave.holding_registers
    case mode
    when "temp"
      regs[2] = value
    when "power"
      regs[22] = value
    else
      # type code here
    end
    sleep 0.1
  end
end