Home Modbus

RTUServer.rb

# Set up the serial
require 'rubygems'
require 'rmodbus'

# Start Modbus server
srv = ModBus::RTUViaTCPServer.new(10002,1, {:host => "0.0.0.0"})
srv.start

# Data
data = [ 0 ] * 15
srv.holding_registers = data

# Set up serial interface
mstr = ModBus::RTUClient.new("/dev/ttyS0", 9600)
slave = mstr.with_slave(1)

# Loop
while (true) do
  # Time Loop
  time_start = Time.now.to_f

  # Volts
  data[0..1] = slave.holding_registers[769..770]

  # Amps
  data[2..3] = slave.holding_registers[781..782]

  # kWh Energy
  data[4..5] = slave.holding_registers[805..806]

  # Power Factor
  data[6] = slave.holding_registers[0x33d][0]

  # Power Factor Sector
  data[7] = slave.holding_registers[0x33f][0]

  # Hz
  data[8] = slave.holding_registers[0x339][0]

  # Active Power - Watts
  data[9..10] = slave.holding_registers[0x319..0x31a]
  data[11] = slave.holding_registers[0x347][0]

  # Reactive Power - VAr
  data[12..13] = slave.holding_registers[0x31d..0x31e]
  data[14] = slave.holding_registers[0x34c][0]

  # End Timing
  time_duration = Time.now.to_f - time_start

  # Update server
  srv.holding_registers = data

  # Notify
  puts "Updating data, run took #{time_duration} seconds..."
  puts data.collect { |d| d.to_s }.join(",")

  # Delay
  sleep(5 - time_duration) if (time_duration < 5)
end

# End Modbus Server
srv.shutdown