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 who demand accuracy — 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 (optional add-on below).

SKUs: plex-pkm-v3-b | plex-pkm-v3-hd

Add-Ons/Replacement Parts

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THE ORIGINAL KNOCK MONITOR

PLEX KNOCK MONITOR®V3

PRECISE. PROVEN. PRO.

Built on over 12 years of knock detection expertise, the PLEX KNOCK MONITOR® V3 is a professional knock detection and analysis system designed from the ground up for data-driven tuners, engine calibrators, and motorsport engineers.

At its core: a proprietary detection algorithm and hi-fidelity audio filtering that isolates knock from mechanical noise with precision conventional methods can’t match. Paired with advanced PC-based analysis tools, it gives you everything you need — from signal capture to cross-cylinder analysis — in one compact, field-proven system.

Knock Monitor V3 and all included accessories laid out, including sensor, cables, flash drive, and connectors.

WHAT'S NEW? EVERYTHING.

POWERFUL PROCESSOR

A new high-speed multi-core processor handles sub-systems such as Comms, CAN bus decoding, math channels and sensor signals independently ensuring peak performance in any setup.

ADVANCED KNOCK
DETECTION SETTINGS

Set signal gain per cylinder and per sensor, and configure detection windows synchronised to engine position — for precise, engine-specific knock identification

DEDICATED MULTI-CORE DSP

Equipped with a new DSP core, the system delivers enhanced audio signal processing and enables advanced knock detection algorithms for greater precision.

ENHANCED PER CYLINDER DETECTION

Achieve significantly more accurate knock monitoring for each cylinder, leveraging the engine position signal input for precise analysis.

HIGH FIDELITY
AUDIO FILTERING

Steep high pass filters that isolate knock from background noise can be selected for different type of engines.

ENGINE POSITION
SIGNAL DECODING

Seamlessly integrates with existing crank and cam trigger signals to provide accurate engine speed and position inputs.

ENTIRELY CONFIGURABLE

Intuitive, yet in-depth configuration lets you customise the UI, CAN Bus, Comms, I/Os, and other functions to match your exact needs — for any vehicle setup.

100Mbit ETHERNET

Ultra-fast, real-time data streaming to your PC with electrical isolation. Ideal for engine dyno setups where the device is mounted away from the PC.

INDUSTRIAL M8 CONNECTORS/
WIRING SYSTEM

Featuring a new and improved wire loom with robust industrial M8 connectors, this system enhances reliability and simplifies device setup for seamless operation.

POWERFUL PC ANALYSIS SW

Now compatible with our PDA-WIN Data Analysis & Visualisation software, enabling high-level real-time or cross-analysis on your PC.

FULLY CONFIGURABLE
RGB LED LIGHTS

Four customizable RGB LEDs provide clear visual warnings and status indicators for device health and knock alarms, ensuring you stay informed at a glance.

CAN BUS DATA LOGGING

Fully configurable datalogging with conditioned based logging. Log up to 256 data channels and 256 flag channels for post review and analysis on the PC.

INDUSTRIAL QUALITY
MEMBRANE KEYPAD

Featuring a membrane keypad with configurable functions, the new Knock Monitor delivers solid tactile feedback for a reliable user experience.

2.8” ULTRA BRIGHT IPS DISPLAY

High-brightness, high-contrast IPS screen for clear viewing of real-time knock data and logged files on the spot.

BUILT TO LAST

Constructed with high-quality components, the new Knock Monitor offers frequent firmware and feature updates, backed by robust support to ensure longevity and reliability.

KEY APPLICATION AREAS

Knock detection sits at the heart of any serious engine development or tuning programme. Identifying detonation early — before it shows up as power loss or engine damage — requires more than a good ear. It requires accurate signal capture, reliable filtering, and the tools to analyse what you’re seeing.

Whether you’re optimising ignition timing on a high-compression build, validating combustion behaviour on a dyno, or monitoring a race engine at the limit, the data the PLEX KNOCK MONITOR® V3 delivers is what separates informed decisions from guesswork.

Used across a wide range of professional applications:

PERFORMANCE TUNING
AND ENGINE CALIBRATION

Giving tuners the tools to work accurately and safely — diagnosing combustion issues and validating results across a wide range of platforms.

AFTERMARKET PRODUCTS
& ENGINE CALIBRATION

Fine-tuning race engines to the edge of their capability, with real-time knock monitoring available during testing and competition.

OEM DEVELOPMENT
AND TESTING

Validating engine designs, combustion systems, and emissions compliance during the development cycle of new vehicle programmes.

MOTORSPORTS

Fine-tuning race engines to the edge of their capability, with real-time knock monitoring available during testing and competition.

RESEARCH & DEVELOPMENT

Studying combustion phenomena, testing alternative fuels — hydrogen, biofuels, synthetic blends — and developing next-generation combustion strategies.

INDUSTRIAL ENGINES

Protecting stationary and marine engines in power generation and heavy-duty applications from detonation-induced damage.

EDUCATION

A practical teaching tool for automotive engineers and technicians studying combustion dynamics and engine management.

RUGGED. ROBUST. PRO.

A Future-proof, Cutting Edge Hardware Platform.

The V3 was designed and built from the ground up — new processor architecture, new DSP core, new wiring system, new enclosure. Every hardware decision was made with longevity and scalability in mind, ensuring the platform can support new features and evolving user needs through firmware updates well into the future.

PLEX Knock Monitor V3 side-by-side front, back and side views showing display, keypad interface and connector ports.

2.8`` IPS TFT Display & Custom UI

View knock events clealy in real time via the new wide-angle IPS display. Configure display pages according to your preferences.

Industrial Quality Membrane Keypad

Highly-ergonomic membrane keypad let you control the device easily.

RGB LED Lights

Four configurable RGB LED lights can be programmed for device status and custom knock warnings/alerts.

Mounting Screw

1/4″ -20 threaded hole for effortless mounting with custom holders
or easily available suction cap holders.

High-quality Cables/Connectors

Industrial quality M8 connectors with new high-quality cables for the Knock Sensors, Trigger Input, IOs, Power and CAN Bus.

Cable Holder Bracket

Sturdy aluminum cable holder bracket prevents stress or damage to the device connectors.

USB Port

Convenient USB type C port for device configuration and short-range real-time data streaming.

Audio Output

3.6mm audio jack. Plug-in your headset and list to knock in raw or filtered format.

100Mbit Ethernet

Ultra-fast, long-distance streaming of device data via Ethernet. Ideal for engine Dynos.

USB Datalogging

32Mb micr0-SD card for seamless datalogging.

A Future-proof,
Cutting Edge Hardware.

We have literally built the new PLEX Knock Monitor from scratch, leveraging the latest advancements in electronics and signal processing to ensure unmatched performance and reliability. Designed with scalability and future updates in mind, the hardware is ready to adapt to evolving technologies and user needs. Whether you’re tuning engines today or preparing for the challenges of tomorrow, this is the tool that keeps you ahead of the curve.

Mobile-optimized stacked image of Knock Monitor V3 showing front, back, and side profiles.

RGB LED Lights

Four configurable RGB LED lights can be programmed for device status and custom knock warnings/alerts.

2.8`` IPS TFT Display & Custom UI

View knock events clealy in real time via the new wide-angle IPS display. Configure display pages according to your preferences.

USB Datalogging

32Mb micro-SD card for seamless and convenient datalogging.

Industrial Quality Membrane Keypad

Highly-ergonomic membrane keypad let you control the device easily.

Mounting Screw

1/4″ -20 threaded hole for effortless mounting with custom holders
or easily available suction cap holders.

High-quality Cables/Connectors

Industrial quality M8 connectors with new high-quality cables for the Knock Sensors, Trigger Input, IOs, Power and CAN Bus.

100Mbit Ethernet

Ultra-fast, long-distance streaming of device data via Ethernet. Ideal for engine Dynos.

Cable Holder Bracket

Sturdy aluminum cable holder bracket prevents stress or damage to the device connectors.

USB Port

Convenient USB type C port for device configuration and short-range real-time data streaming.

Audio Output

3.5mm audio jack. Plug-in your headset and list to knock in raw or filtered format.
EMBODIED KNOCK SCIENCE.

IDENTIFY, PINPOINT & ANALYZE
KNOCK BETTER THAN EVER BEFORE.

Our proprietary algorithm and hi-fidelity audio filtering work together to capture, isolate, and analyse knock events with a level of accuracy and detail that conventional systems can't reach. See it in action.

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BEYOND KNOCK.

A FULL-SCALE CAN BUS DATALOGGER

The PLEX KNOCK MONITOR® V3 is more than a knock detection system — it’s a full CAN bus datalogger. Logging directly from your vehicle’s CAN bus, it synchronises knock events with performance data from OEM or aftermarket ECUs, giving you a complete, data-driven picture of combustion health, diagnostics, and engine behaviour — all in one compact system.

  • FULLY CUSTOM CAN BUS RECEIVE
  • FULLY CUSTOM CAN BUS TRANSMIT
  • UP TO 256 DATA CHANNELS
  • UP TO 256 FLAG CHANNELS
  • 2x ANALOG/DIGITAL INPUTS (0-5V)
Front view of PLEX Knock Monitor V3 displaying ECU data logging and "Logging Started" message on screen.

EASE OF USE

ON-DEVICE SETUP, NEW UI
AND EXAMPLE LAYOUTS

The PLEX KNOCK MONITOR® V3 supports on-device configuration for core settings, so you can get up and running without a PC. For advanced configuration, PLEX Device Manager on PC gives you full control over every parameter.

Load example configuration files and pre-designed page layouts tailored for common tuning scenarios to get started even faster.

ON DEVICE CONFIGURATION OPTIONS

  • Trigger: source & pulses per rev
  • Knock Mode: frequency, signal gain & threshold mode
  • Audio: filter, channel mix & volume

NEWLY IMPROVED GRAPHICS

  • Enhanced customisation
  • More graphical objects
  • More pre-designed page layouts
ANALOG OR CAN BUS

SEAMLESS DYNO
INTEGRATION

Connect the PLEX KNOCK MONITOR® V3 to your dynamometer via 0-5V analog outputs or CAN Bus — compatible with a wide range of dyno systems. Both interfaces deliver precise, synchronised knock data in real time during testing.

KNOCK OUTPUT DATA

  • Signal Amplitude per sensor
  • Knock Signal per sensor/cylinder
  • Knock Intensity per sensor/cylinder
  • Knock Count per sensor/cylinder
  • Knock Rate per sensor/cylinder
LISTEN AND LEARN

PODCAST: PROPERLY
UNDERSTAND KNOCK

“It’s something that can destroy your engine in seconds… but how much do you really know about pre-ignition, knock, and super-knock”? On this episode of the Tuned In podcast, Andre from the HP Academy has invited Ioannis Andrianakis (PLEX TUNING’s founder & CTO) to discuss through these terms, how his highly-regarded series of knock monitors work, and what one does and does not need to worry about when it comes to all things detonation.

Listeners will gain valuable insights into the causes, solutions, and nuances of engine knock as Andre and Ioannis dive deep into this critical topic—a must-listen for performance tuners!

PLEX DEVICE MANAGER 2.0

YOUR KNOCK MONITOR. YOUR WAY.

Advanced Configuration at Your Fingertips.

ENGINE & SENSORS SETUP

The engine and sensor configuration window enables seamless device adaptation to any engine type. From basic single-sensor setups to advanced dual-sensor configurations with individual cylinder assignments and independent sensitivity adjustments, it offers unmatched flexibility.

CRANK TRIGGER SETUP

The crank signal decoding configuration window supports a wide range of common OEM crank and camshaft signal patterns, ensuring seamless integration with various engine setups. Advanced signal processing allows precise synchronization for accurate knock detection, even in complex configurations.

KNOCK THRESHOLD CALIBRATION

In manual knock threshold mode, the dedicated calibration window provides a streamlined interface for setting threshold points. Live streaming of knock signal data from the engine ensures precise configuration and real-time feedback.

EASY TO NAVIGATE
SETUP TREE INTERFACE

A hierarchical tree-list interface offers an intuitive and organized way to access all device configuration options. This logical flow simplifies complex setups, allowing users to navigate effortlessly through various configuration layers.

COMMON USER INTERFACE
FOR ALL PLEX DEVICES

The PDMv2 provides a unified interface across all PLEX devices, from dashboards to tuning tools. This consistency ensures easy switching between devices and streamlines configuration with a shared layout and features.

WYSIWYG DASH PAGE
LAYOUT DESIGN

Enjoy a ``What You See Is What You Get`` dash page layout, allowing for easy offline design with accurate page previews. Data simulation ensures users can see exactly how their dashboards will look and function, providing full confidence in the final setup.

TRULY FAST CONFIGURATION

Speed up the configuration process with easy filtering of selection lists, keyboard shortcuts, and copy-paste functionality. These tools help streamline & accelerate setup, minimizing time spent on repetitive tasks.

REAL-TIME CAN MSG STREAMING

Transform your device into a powerful CAN bus diagnostic tool with real-time streaming of incoming raw CAN messages. View all incoming data instantly, and transmit user-defined CAN messages on demand for advanced troubleshooting and system testing.

BUILT-IN TEMPLATES

The software comes preloaded with a comprehensive library of CAN protocol templates for seamless connection to most aftermarket ECUs. It also includes sensor templates for common engine sensors, allowing for quick and easy setup without manual configuration.

PLEX PDA-WIN®
KNOCK ANALYSIS
& VISUALISATION SW

See. Listen. Understand.

WAVEFORM GRAPH

The Knock Waveform Graph displays unprocessed knock sensor signals, trigger signals, and the calculated cylinder number, providing a comprehensive visual tool for verification and troubleshooting. This ensures accuracy and simplifies diagnostics in complex setups.

FREQUENCY SPECTOGRAM

The Knock Frequency Spectrogram offers a graphical representation of signal frequency content, enabling users to detect knock events and identify primary and harmonic knock frequencies. This helps in selecting the frequency that delivers the best signal-to-noise ratio for precise monitoring.

KNOCK vs RPM

The Knock vs RPM Graph presents a clear visualization of knock data during a dyno sweep, offering insights into engine performance. Users can easily adjust the knock threshold line manually or automatically, leveraging collected data for optimal calibration.

CUSTOMIZABLE UI

User defined layout of tabs and panels with handy docking similar to latest Windows SW suite and also light & dark modes.

FAST KEYBOARD SHORTCUTS

Main menu and panel functions shortcuts speed up the set-up time and the dynamic real-time analysis considerably.

MULTIPLE GRAPHS & PANELS

A wide array of chart types lets you visualise large amounts of data into an easy to understand formats and bring out insights at a glance.

EASY FILE COMPARISON

Seamlessly switch between single and comparison view even for completely different file types such as a dyno run with a track lap.

LIVE DATA UPDATING

Zoom levels & cursors are synchronized across all analysis panels and graphs, enabling auto rescaling and seamless cross-referencing of data.

SMART TUNING MAPS

Configurable cell graphs with information directly transferable to the ECU calibration maps that help you optimise your fuel and ignition maps.

KNOCK MONITOR VERSION COMPARISON

PLEX Knock Monitor V3 Basic showing custom knock monitoring page with intensity and knock count data. PLEX Knock Monitor V3 HD version knock display showing a graph with the knock level for each cylinder
KNOCK MONITOR V2 KNOCK MONITOR V3 PLEX KNOCK MONITOR V3
(Discontinued) Basic Version HD Version
Custom CAN BUS --
Knock Sensor Inputs 1-2 2 2
Detection per Cylinder up to 8 Up to 16 Up to 16
Knock Threshold 2D 2D 2D + Advanced
USB Datalogging --
Ethernet -- --
# Data Channels Only Knock 64 256
Engine Position Inputs -- RPM only
Gain per Cylinder -- --
Gain per Sensor -- --
Knock Windowing -- --
Real-time FFT -- --
Configuration SW Own (limited) PLEX Device Manager V2 PLEX Device Manager V2
Analysis SW -- PLEX PDA-WIN V2 PLEX PDA-WIN V2
Connectors JWPF M8/DTM/JWPF M8/DTM/JWPF

DETAILED SPEC

Technical drawing of PLEX Knock Monitor V3 showing front, side, and rear views with dimensions.
Physical
Dimensions (mm) w 132 x h 76 x d 126
Weight 250g
Connector(s) M8 Power/CAN
M8 Knock Signals
M8 Trigger/In-Out/5V-sgnd
Material CNC machined aluminum
Sealing/Ingress Protection IP5x
Electrical Data / Operating Conditions
Supply Voltage Range 9-30V DC
Current Consumption max. 2A at 12V
Temperature Range -20 to +60 degC
Screen
Type RGB TFT IPS Wide-Temp
Size (px) 240 x 320
Brightness 900cd
Refresh Rate 50Hz
Communications
CAN Bus 1x
USB-C 2 (for configuration/streaming & logging)
Ethernet 100Mbit (HD version only)
Inputs/Outputs
Knock/Vibration Sensor 2x
Analog Inputs 0-5V 2x (shared)
Digital Inputs 0-5V 2x (shared)
Engine Position/Trigger VR/hall Inputs 2x (HD version only)
Analog Outputs 0-5V 2x (shared)
LEDs 4x RGB (configurable)
Internal Sensors
Real Time Clock with battery backup
Device/Sensor Voltage Monitor +12V supply/+15V sensor supply
Device Temperature Sensor Yes
Ambient Light Sensor
Data Logging
Memory USB flash drive or PC Logging
Max. Log Rate
  • 44κHz knock/vibration
  • 100Hz other data
Data Channels
Max. Data Channels 64 (Basic), 256 (HD)
Max. Flag Channels 64 (Basic), 256 (HD)
User Interface
# of Pages 24
Custom Page Design yes
Custom Themes yes
Pre-loaded Templates/Pages yes
Internal Calculations
Knock Metrics
  • Signal Amplitude per sensor
  • Knock Signal per sensor/cylinder
  • Knock Intensity per sensor/cylinder
  • Knock Count per sensor/cylinder
  • Knock Rate per sensor/cylinder
Knock Frequency Analysis Real-time/cylinder (HD version only)
Math Channels 4 (Basic) , 8 (HD)

DEVICE COMPATIBILITY

DYNAMOMETERS

The PLEX KNOCK MONITOR® V3 seamlessly integrates with dynamometers for enhanced testing and analysis.

  • Real-time Knock Data Output: Transmit calculated knock data to a dynamometer in real time using either the two analog outputs or the configurable CAN bus transmit functions.
  • Dynamometer Data Input: Receive torque, power, and other available channels via CAN from compatible dynamometers that support this functionality.

This two-way communication enables precise correlation between knock events and engine performance metrics, optimizing tuning accuracy.

Knock Related Output Data

  • Signal Amplitude per sensor
  • Knock Signal per sensor/cylinder
  • Knock Intensity per sensor/cylinder
  • Knock Count per sensor/cylinder
  • Knock Rate per sensor/cylinder
ECUs - Aftermarket
Adaptronic
AEM
  • Infinity
  • Series 2
Bosch Motorsport
  • MS3
  • MS40
Carrot
DTA
  • S Series
  • T Series
ECUMASTER
  • EMU Black
  • Classic
  • Pro
EFI
  • EFR18
  • Euro1
  • Euro4
  • Euro6
  • Euro8
Electromotive TEC
Emerald
  • K3
  • K6
Emtron
E-Race Black
GEMS
Haltech
Hondata
  • Kpro
  • S300
KMS
  • MD35
Life Racing
LINK
  • G3
  • G4
  • G4X
MAXX
MARELLI
Mectronic
  • MKE1
  • MKE4
  • MKE6
  • MKE7
Megasquirt
Microtech
  • v2.0
MMe
  • ECU481
MOTEC
  • M400
  • M600
  • M800
  • M1 Series
Pectel
  • EQ10
  • SQ6
Specialist
Components
SYVECS
  • S6
  • S7
  • S8
Triject
ECUs - OEM
BMW M2/M4
MItsubishi Evo X
Toyot GT86
ECUs - Generic OBDII/UDS
OBD – CAN ISO15765
OBD – MODE 22 MANUFACTURER SPECIFIC PIDS
OBD – UDS
J1939
NMEA2000
PDUs
PDU Ecumaster
PDU HP Elektronic
PDU Life Racing
PDU Motec
PDU Syvecs
PDU Tremondi
PDU MSEL Master Relay
Auxiliary Devices
ABS Bosch Motorsport M4/M5
DCU Motec MDC/MDC2
KEYPAD Blink Marine
KEYPAD Tremondi
LAMBDA AEM
LAMBDA Ecumaster
LAMDA Haltech
LAMBDA Link
LAMBDA Motec
SENSOR AEM Thermocouple Amplifier
SENSOR KMS Thermocouple Amplifier
SENSOR KMS Flex Fuel
SENSOR KMS Speed Sensor
SENSOR Motec E888
SENSOR Syvecs Thermocouple Amplifier
SENSOR TEXENSE IRN4C/IRN8C/THN4X
SENSOR AIM TPMS
SENSOR IZZE TPMS
TCU XAP ESHIFT2

QUESTIONS? ANSWERS.

Documentation
Datasheet download
Pin-out Diagram download
Technical Drawing download
User Manual access
Software
PLEX Device Manager 2.0 download
PLEX Data Analysis 2.0 (PDA-WIN) download
What's In the Box?
1. Device
2. USB-C to USB Cable
3. 4m dual Knock Cable
4. 2m Trigger/IOs Cable
5. 2m Power/CAN Cable
6. Bosch Knock Sensors (optional)
7. Connectors & Pins
8. USB Stick Kit

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