Rotary Dial Tester

Testing & adjusting mechanical rotary dials using Web Serial and an RS-232 interface
not connected
Status
nsi (DCD)
nsr (DSR)
nsa (RI)
Digit-
Pulses0
Diagram0/10
Pulse frequency 0.0 Hz
Nominal 10 Hz (tolerance 9.1-11.1 Hz)
Pulse/pause ratio 0% nsi closed
Display equals (pause / (pulse+pause)) - warning outside 10-70%
Pulses (1...10)
Note: For frequency testing, choose digits 2-0 (1 is not a full period).
Controls
Note: Unlocks after 10 diagrams with the same digit. Runtime shows timing spread across 10 cycles; pulse/pause lists min/max and delta per period.
Diagrams
No diagrams yet.
Help - COM/Program

Browser: WebSerial works in Chromium-based browsers (Chrome, Edge). The page must run over https:// or http://localhost.

Signals (hardware mapping):

Usage: 1) "Connect COM", 2) "Start Test", 3) dial digits 2-0. After each dial a diagram is created.

Debounce (EP): Corresponds to the additional wait time between two signal reads for DCD. EP1 is the default. Higher values can compensate bounce but distort the overall measurement.

Analysis: If 10 diagrams in a row with the same digit are captured, both analyses are enabled.

Rotary dial testing and adjustment: