a working serial program.

tester.rb

#!/usr/bin/ruby
#encoding: utf-8
require "serialport"

ENABLE_RS485_RELAY = true
DEV=0
BAUD=57600
MSG_SLEEP_TIME = 0.1

trap("INT"){exit 0}
trap("TERM"){exit 0}


class String
  def to_bin
    [self].pack("H*")
  end

  def to_hex
    str=""
    self.each_byte{|b| str << b.to_s(16).add_zero }
    str
  end

  def add_zero
    self.length == 1 ? "0" + self : self
  end
end


def rs485_send(msg, baud, dev, parmas={})
  #sp = SerialPort.open(dev, baud, 8, 1,  SerialPort::MARK)
  sp = SerialPort.open(dev, baud, 8, 1,  SerialPort::MARK)
  sp.write "01fdfd".to_bin
  sp.close
  sleep MSG_SLEEP_TIME
  #sp = SerialPort.open(dev, baud, 8, 1,  SerialPort::SPACE)
  sp = SerialPort.open(dev, baud, 8, 1,  SerialPort::EVEN)
  sp.write msg.to_bin
  puts msg.length
  sp.close
end



rs485_data = "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"
puts rs485_data
rs485_send(rs485_data, BAUD, "/dev/ttyS0")