require "timeout"
class UsbTmc

def initialize(adrs=0)
  @port=open("/dev/usbtmc%d"%adrs,"r+")
  each_init
end

def finish
  @port.close
end
def each_init()
  # initialization for each instrument
end

def talk(str)
  begin
  timeout(1){
      @port.write(str)
      @port.flush
    }
  rescue TimeoutError
    puts "write timeout error at #{Time::now} on USB with '#{str}'"
  end
end

def listen(n=256)
  begin
    timeout(1){
      @port.readpartial(n)
    }
  rescue TimeoutError
    puts "read timeout error at #{Time::now} on USB"
    return 0
  end
end

def idn()
  talk(sprintf("*IDN?"))
  listen()
end
#def init()
#	talk("*CLS")
#end
#def reset()
#	talk("*RST")
#end

end #class