PLEX Knock Monitor® V3

Never Miss Knock Again.

The PLEX KNOCK MONITOR® V3 is a professional knock detection and analysis system built for engine tuners, calibrators and motorsport engineers — from street builds to full race programmes. Powered by hi-fidelity audio filtering and a proprietary detection algorithm refined over 12 years. Compatible with gasoline, diesel and alternative fuel engines.

*Knock sensors are not included — add 1 or 2 sensors with the Sensors option.

Key Features

• Proprietary PLEX knock algorithm — leading professional knock detection since 2010, isolating knock from mechanical noise.
• Hi-fidelity audio filtering — steep high-pass filters selectable for different engine types, with 3.5mm headphone output for raw or filtered audio.
• Powerful multi-core processor & dedicated DSP — comms, CAN decoding, math channels and sensor signals handled independently for peak performance.
• Per-cylinder detection up to 16 cylinders — signal gain per cylinder and per sensor, with detection windows synchronised to engine position.*
• Engine position signal decoding — integrates with existing crank and cam trigger signals for accurate speed and position.*
• Real-time FFT frequency analysis — per-cylinder frequency content on device.*
• Full CAN bus datalogger — fully custom CAN receive/transmit, up to 256 data and 256 flag channels, condition-based USB logging.
• 2.8" ultra-bright IPS display — 900cd high-contrast screen with configurable pages and four programmable RGB status LEDs.
• 100Mbit Ethernet — electrically isolated, long-distance real-time streaming, ideal for engine dyno cells.*
• Seamless dyno integration — 0-5V analog outputs or CAN bus output of amplitude, knock signal, intensity, count and rate per sensor/cylinder.
• Industrial M8 wiring system — CNC machined aluminum enclosure, M8 connectors, aluminum cable holder bracket, 1/4"-20 mounting thread.
• PLEX Device Manager v2 + PDA-WIN analysis — on-device setup for core settings plus full PC configuration, waveform graph, frequency spectrogram and knock-vs-RPM threshold calibration.

*HD version only or extended on the HD version.

Basic vs HD

• Basic — 2 knock sensor inputs, detection up to 16 cylinders, 2D knock threshold, USB datalogging, RPM-only engine position input, 64 data / 64 flag channels, 4 math channels.
• HD — everything in Basic plus 100Mbit Ethernet, 2x VR/hall engine position inputs, gain per cylinder and per sensor, knock windowing, real-time FFT, advanced knock threshold, 256 data / 256 flag channels, 8 math channels.

Upgrade Options (Upgrade Only — No Device Included)

Important: Model choices beginning with "UPGRADE ONLY" are priced for the upgrade license alone. They do not include a device. They apply to a PLEX unit you already own, are issued against your host device's serial number, and are applied via PLEX Device Manager v2 — no hardware to send in.

• Base → HD — converts a Knock Monitor V3 Base unit you already own to full HD specification: 100 Mbit Ethernet, engine position inputs, gain per cylinder/sensor, knock windowing, real-time FFT and the complete HD analysis feature set. Sensors are not included with the upgrade.

Installation and Configuration available at Race Protocol

Authorized dealer with in-house installation, wiring and calibration. Call (724) 732-8948 to discuss your build.