OpenDRO User's Guide

2 Features

OpenDRO incorporates a very large feature set and the major features are summarized below.  You can find more detailed information in the sections that follow.


  • Support for Chinese (24BIT, 21BIT, BCD7, and BIN6 protocols) and quadrature scales
  • Chinese scale protocol auto-detection
  • Fast scale reading for Chinese scales with a display update rate of up to 50 times a second
  • Scale summing
  • Adaptive moving average scale filtering to minimize jitter
  • Linear error correction


  • Absolute and incremental zeros
  • Enter zero values for both coordinate systems via keypad
  • Enter incremental presets via keypad
  • Enter fractional numbers via keypad
  • Zero warning with axis blink and piezo buzzer
  • Electronic edge finder zeroing with audible alert


  • Display units in inches or millimeters (mm)
  • Configurable display precision up 4 decimal places in inch mode (3 for mm mode)
  • Auto-precision to automatically reduce precision to fit the display
  • Fractional display in 64ths
  • Raw scale count display
  • Feed rate display in inches per minute or millimeters per minute
  • Tachometer display in RPM or surface feet per minute (SFM)
  • Display brightness configurable in 20% increments


  • Tool offsets
  • Bolthole circles
  • Sub-datum workspaces
  • Hole grids
  • Radius cutting (concave and convex)
  • Compound vectoring
  • Centerline calculation
  • Diameter mode
  • Auto power off and on


  • USB and RS-232 serial interfaces
  • Software upgradeable
  • Lua command interface
  • Run Lua scripts from keypad
  • SD memory card support (SD and SDHC)
  • Lua shell with advanced editing (edit keys, history, and completion)
  • Windows virtual DRO application to control DRO remotely


  • Reverse polish notation (RPN) calculator with a 4 level stack
  • RPN calculator operations: addition, subtraction, multiplication, division, cosine, sine, tangent, square root, power, memory, scale transfer, fractions, and more
  • Audible key presses

.. and more!