instrument-control >> Low level I/O functions
Serial
  serial
  srl_read
  srl_write
  srl_baudrate
  srl_bytesize
  srl_flush
  srl_parity
  srl_stopbits
  srl_timeout
  srl_close
I2C
  i2c
  i2c_addr
  i2c_read
  i2c_write
  i2c_close
Parallel
  parallel
  pp_datadir
  pp_data
  pp_ctrl
  pp_stat
  pp_close
