MicroScribe Arm Tester
Check that your MicroScribe is talking to this computer — no download, no install. Connect the arm, move the stylus, press the buttons, and copy the results for Revware support.
The page reads the arm directly in Chrome or Edge — a USB arm over USB, a serial arm (MicroScribe 3D, 3DX or G2) through its COM port or a USB-serial adapter — and draws the stylus, the joint encoders and the buttons live. Nothing is uploaded: the connection stays on your machine, and the diagnostic goes only where you paste it.
Before you click Connect
- USB arm: plug in directly to a computer USB port or hub. Serial arm: power it on and connect its cable to a COM port or a USB-serial adapter (install the adapter's driver first; tested with a Prolific PL2303-based adapter, and FTDI-based adapters are an alternative).
- Chrome or Edge on a Windows or Mac desktop or laptop, or a Windows tablet. Other browsers cannot open USB devices or serial ports.
- Close MUS and any other program that uses the arm or its COM port — only one program can hold it.
- Home the arm (press Home on the base if its LED is red) and leave it resting in the home position until the page says it is connected.
Connect and move the stylus
Common reasons the arm does not appear
The Connect buttons are greyed out or the status says WebHID or Web Serial is not available
This browser cannot open USB devices or serial ports. Use Chrome or Edge on Windows, macOS or Linux — not Firefox or Safari, and not a phone or an Android or Apple tablet.
USB arm: the chooser opens but the list is empty
The computer is not seeing a MicroScribe on USB. Check the cable at both ends, try another USB port (or plug in without a hub), and make sure the arm's power LED is on. A serial arm does not appear here — use the Connect a serial arm button for it.
Serial arm: I do not know which COM port to pick
The chooser lists port names only. With a USB-serial adapter, open the chooser, then unplug the adapter and plug it back in: the entry that disappears and returns is the arm's port. On a computer with a built-in serial port there is usually only one entry. Pick the wrong one and the page simply reports that no MicroScribe answered — try the next.
Serial arm: "No MicroScribe answered on that port"
Check that the arm is powered (base LED on) and homed, that the serial cable is seated at both ends, that the adapter's driver is installed (the port must appear in Device Manager or System Information), and that you picked the arm's port. Then click Connect again — the arm answers the sign-on even after an earlier session was cut short.
The arm is listed, but connecting fails or the status says it is held by another program
Another program has the arm or its COM port open. Close MUS, RevWorks, any CAD plug-in, any ArmDLL program or terminal, unplug and replug the arm or adapter, then click Connect again.
It connects, but the numbers do not change when I move the arm
Move the stylus a few inches — the arm only reports while it is moving (a serial arm's report rate reads idle while it rests). If nothing changes, unplug the arm, wait five seconds, plug it back in and reconnect. If it still does not change, copy the diagnostic and send it to us.
Some dials move, one does not
Move that joint on its own through a good part of its range. A dial that never moves while its joint turns points at that joint's encoder or wiring — copy the diagnostic with that joint moved and send it to us.
The dials show odd angles after connecting
The dials are zeroed on the pose at the moment of connection, so the arm must be resting in the home position when you click Connect. Put it there and press Set dial home, or disconnect and reconnect.
A button does not light
Press it firmly a few times; the indicator lights while it is held. Button 3 exists only on USB arms with a current-generation control board, so on older arms it will never light — that is normal, and serial arms show two buttons only. If button 1 or 2 never lights, note it in your message to us.
Built on the same browser kinematics core Revware is preparing for a future MicroScribe SDK release (coming soon). Questions: contact Revware.
MicroScribe® is a registered trademark of Revware, Inc.