Mach3 Jog Rate: Configuring SetOEMDRO Buttons in VB

How SetOEMDRO Controls the Jog Rate

Mach3 exposes its on-screen data readouts (DROs) to the built-in VB scripting engine through the SetOEMDRO call. OEM DRO number 3 is the jog rate, expressed as a percentage. Writing a value to that DRO from a button script changes the active jog rate immediately, without opening any settings dialog.

The confirmed behavior from field use: calling SetOEMDRO(3, 5) sets the jog rate to 5%. The second argument is the target percentage, so the same call with a different value sets a different rate. This is the only OEM DRO number validated by the source evidence; treat any other DRO number as unverified until you confirm it against the official Mach3 documentation or test it on a non-production machine.

Creating the Jog Rate Buttons

Add one button per preset jog rate to the Mach3 screen, and place the VB call in each button's script. A typical two-button pair looks like this:

Call SetOEMDRO(3, 5)   'Set jog rate to 5%
Call SetOEMDRO(3, 50)  'Set jog rate to 50% (adjust value as required)

1. Open the screen in the Mach3 screen designer and add a button where the operator needs it.
2. Mark the button as a VB-scripted button rather than a fixed function button.
3. Open the button's script in the VB script editor and enter the Call SetOEMDRO(3, n) line with the desired percentage.
4. Save the screen set, return to Mach3, and reload the screen if necessary.
5. Press the button and confirm the jog rate DRO on screen updates to the new percentage, then verify with a short jog move.

Verification and Open Questions

Verification is direct: after pressing the button, the jog rate DRO must display the new percentage, and an actual jog move must reflect the changed speed. If the DRO does not update, confirm the button is configured to execute VB and that the script was saved with the screen set.

Two questions raised in the field report have no evidence-backed answer. First, a complete reference of all VB hooks and OEM DRO numbers is not reproduced here; only DRO 3 is confirmed, so consult the official Mach3 documentation for the full list. Second, binding the script to a physical USB numeric-pad key is not covered by the evidence. The decision path is to determine how your Mach3 installation maps external inputs (key emulator, MPG, or input signals) to screen buttons, then point that mapping at the scripted button. Test the mapping while the machine is in a safe state before relying on it during operation.

FAQ