Glossary
Data Logging Glossary
A-Z: Technical terms, technologies and processes
This glossary provides a compact overview of important terms and concepts in the field of data logging. It serves as a reference work to better understand technical contexts and to facilitate the use of data loggers and data acquisition systems.
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1000BASE-T1
An automotive Ethernet standard for gigabit data transmission (1 Gbit/s) via a single twisted pair of wires. 1000BASE-T1 is often used in modern vehicle architectures to transmit high data rates (e.g. from cameras, radar or lidar sensors).
1000BASE-TX
An Ethernet standard for the transmission of 1 Gbit/s via two twisted wire pairs (copper, typically Cat6). In the automotive environment, 1000BASE-TX plays a subordinate role to 1000BASE-T1, but is used in test benches, laboratory environments or back-end systems for high-speed data logging.
100BASE-T1
An automotive Ethernet standard for 100 Mbit/s via a single twisted pair of wires. It is widely used in electronic control units (ECUs) and sensor/actuator networks. For data logging, 100BASE-T1 enables robust and cost-efficient data transmission at medium data rates.
A
Sampling rate
The sampling rate describes the number of measured values that are recorded per unit of time (e.g. Hz or kHz). In data logging, it determines the temporal resolution of a signal. If the sampling rate is too low, relevant signal components may be lost (aliasing), while a high sampling rate generates larger data volumes and places higher storage and transmission requirements.
ADAS (Advanced Driver Assistance Systems)
Driver assistance systems that support the driver or partially take over driving functions (e.g. emergency brake assist, lane departure warning, adaptive cruise control). ADAS systems generate large amounts of sensor data (camera, radar, lidar), which is often recorded and analyzed using data logging as part of development, validation and validation.
Analog (analog signals)
Continuous electrical signals whose amplitude represents a physical measured value (e.g. voltage proportional to pressure or temperature). For digital data logging, analog signals must be converted into discrete values using an analog-to-digital converter (ADC). Signal quality, sampling rate and resolution of the ADC influence the accuracy of the recording.
ASAM
ASAM (Association for Standardization of Automation and Measuring Systems) is an international organization dedicated to standardizing data formats and communication protocols in vehicle development. Key ASAM standards for data logging include MDF (Measurement Data Format), XCP (Measurement and Calibration Protocol), and CMP (manufacturer-independent communication protocol). These standards ensure interoperability between tools and systems.
ASAM CMP
ASAM CMP (Capture Module Protocol) is a protocol standardized by ASAM for communication between Capture Modules (probes) and Data Sinks (loggers) in measurement and data acquisition systems. Transmitted via Ethernet, CMP enables manufacturer-independent transfer of vehicle bus, sensor, and Ethernet data, ensuring seamless interoperability across different tools and platforms
Recording modes
Recording modes describe the available storage and target systems on which recorded data is stored during a measurement. Different options are available depending on the application and data rate. Typical recording modes are internal memory, external memory or PC via Ethernet.
Automotive Data Logging
Automotive data logging refers to the systematic recording, storage and analysis of vehicle data during development, testing and validation. Among other things, bus communication (e.g. CAN, Ethernet), sensor data, control unit parameters and raw data from ADAS systems are recorded. The aim is to analyze vehicle functions in a traceable manner, diagnose faults and safeguard systems.
Automotive Ethernet
Automotive Ethernet is an Ethernet technology optimized for use in vehicles that enables high data rates with reduced cabling effort. In contrast to classic Ethernet, communication is usually via single-pair cables (e.g. 100BASE-T1, 1000BASE-T1). Automotive Ethernet plays a central role in data-intensive applications such as ADAS and automated driving and is therefore important for high-speed data logging.
AUTOSAR
AUTOSAR (Automotive Open System Architecture) is a globally standardized software architecture framework for electronic control units (ECUs) in vehicles.
C
CAN (Controller Area Network)
CAN is a robust, real-time capable field bus standard for communication between control units in the vehicle. It enables prioritized message transmission at comparatively low data rates (classically up to 1 Mbit/s). CAN is used in data logging to record ECU communication, status information and diagnostic values.
CAN-FD (Flexible Data Rate)
CAN-FD is a further development of the classic CAN standard. It allows higher data rates (up to several Mbit/s) and larger user data fields per message. This means that more information can be transmitted more efficiently. For data logging, this means larger data volumes with higher temporal resolution compared to classic CAN.
CCP (CAN Calibration Protocol)
CCP is a standardized protocol for calibrating, measuring and diagnosing ECUs via CAN. It enables access to internal variables and parameters of an ECU during operation. CCP is used in data logging to specifically record internal ECU measured variables for development and calibration purposes.
Copy station
A copy station is a system for the fast and structured transfer of recorded measurement data from mobile data loggers or storage units to server or backend systems. It is typically used in the development environment to efficiently read out and save large amounts of data and make it available for further analysis.
D
Data Acquisition (DAQ)
Data acquisition (DAQ) refers to the process of recording physical or digital signals using sensors, measurement hardware and corresponding software. This includes signal processing, analog-to-digital conversion, time stamping and storage. In the automotive context, DAQ supplements classic bus recordings with analogue, high-frequency or specialized measured variables.
Data logger
A data logger is a device for recording, time-stamping and storing measurement data. Depending on the design, bus communication (e.g. CAN or Ethernet), sensor data, control unit parameters and analog signals can be recorded. Modern data loggers support high data rates, trigger functions and various storage and transmission concepts.
Data rate
The data rate describes the amount of data that is transferred or stored per unit of time (e.g. bit/s or Gbit/s). In data logging, it determines the requirements for interfaces, storage architecture and system performance. ADAS and Ethernet-based applications in particular can involve very high data rates, which must ensure loss-free processing.
Data sink
A data sink is a device or system that receives data from connected probes or data loggers and stores or processes it centrally. In the XORAYA ecosystem, for example, systems such as the N8000 or N16000 perform this function.
Data storage
A data storage device is the physical or logical medium for the permanent storage of recorded measurement data. This includes SSDs, RAID systems or network storage, for example. In automotive data logging, data storage devices must guarantee high write speeds, reliability and data integrity.
Data validation
Data validation refers to the systematic checking of recorded data for completeness, consistency and plausibility. The aim is to ensure that there are no data losses, time stamp deviations or signal errors. Structured validation is particularly essential for safety-relevant functions and large volumes of data.
Endurance run
Endurance testing refers to long-term tests in which vehicles or systems are operated over extended periods of time under real or simulated conditions. Data logging is used to continuously record operating, diagnostic and environmental data in order to analyze robustness, reliability and malfunctions over time.
Digital Signal
A digital signal consists of discrete, often binary states (0 and 1). In the vehicle environment, digital signals are used to transmit communication data and to display logical states. For data logging, digital signals can be recorded directly and processed without analog-to-digital conversion.
Distributed Data Logging
Distributed data logging describes a distributed recording architecture in which several loggers or recording units work synchronized in a vehicle or test system. The data is recorded locally and later merged or aggregated centrally. This concept is used in particular for complex E/E architectures with high data rates.
DLN (Data Logging Network)
A data logging network (DLN) refers to the networking of several data logging components, such as loggers and storage units. The aim is coordinated, scalable and synchronized data logging within a vehicle or test infrastructure.
DLT (Diagnostic Log and Trace)
DLT is a standardized protocol for the transmission of internal control unit communication. Various applications (e.g. Java and security) run in a control unit. These applications each create their own internal log outputs. These log outputs can be tapped via DLT and logged in the data logger synchronously with the data of the classic bus systems.
DoIP (Diagnostics over IP)
DoIP is a diagnostic protocol that enables vehicle diagnostics via IP-based networks. It replaces or supplements conventional diagnostic communication via CAN. The advantage over the classic bus systems is the higher bandwidth and the associated speed when uploading control unit software.
E
ECU (Electronic Control Unit)
An Electronic Control Unit (ECU) is an electronic control unit that controls, regulates or monitors specific functions in the vehicle (e.g. engine, brakes, ADAS functions). ECUs communicate via vehicle buses such as CAN or Ethernet and are central data sources in automotive data logging.
ESU (External Storage Unit)
A data logging network (DLN) refers to the networking of several data logging components, such as loggers and storage units. The aim is coordinated, scalable and synchronized data logging within a vehicle or test infrastructure.
F
FlexRay
FlexRay is a deterministic, real-time-capable bus system for safety-critical applications in vehicles. It offers higher data rates than classic CAN and supports redundant communication channels. FlexRay is recorded in data logging to analyze time-critical ECU communication.
G
Gbit Ethernet
Gbit Ethernet (Gigabit Ethernet) refers to Ethernet connections with a data rate of 1 Gbit/s. In the automotive context, it is often used in the form of 1000BASE-T1. Gbit Ethernet is relevant for data logging in order to reliably transmit high-resolution sensor data or parallel data streams.
GNSS/GPS
GNSS (Global Navigation Satellite System) is the generic term for satellite-based navigation systems such as GPS, Galileo or GLONASS. They provide position, speed and time information. In automotive data logging, GNSS data is used for vehicle localization, synchronization and contextualization of measurement runs.
gPTP (IEEE 802.1AS)
gPTP (generalized Precision Time Protocol, IEEE 802.1AS) is a specialized implementation of PTP for time-sensitive Ethernet networks. It defines how devices within a local network establish and maintain a common, highly accurate time base.
H
High-speed data recording
High-speed data recording refers to the loss-free recording of very high data rates, typically in the range of several Gbit/s. This is particularly necessary for ADAS, camera, radar or Ethernet raw data. This is particularly necessary for ADAS, camera, radar or Ethernet raw data. The system architecture must guarantee continuous high-performance data processing and storage.
HS-CAN
HS-CAN is a variant of the CAN bus system with data rates of up to 1 Mbit/s. It is used for time-critical control unit communication, for example in the drive or chassis area. In data logging, HS-CAN is used to analyze fast status and control information.
L
LiDAR data
LiDAR data is generated by light-based distance measurement (Light Detection and Ranging). A LiDAR sensor emits laser pulses and measures the time of flight of the reflected signal in order to generate precise 3D environmental information. In automotive data logging, LiDAR raw data is one of the most demanding recording formats due to its high data rate and data volume.
LIN (Local Interconnect Network)
LIN is a serial communication protocol for simple control units and actuators in the vehicle. It is typically used for comfort and body functions (e.g. power windows, seat adjustment). LIN operates at lower data rates than CAN and is recorded in data logging to analyze subordinate subsystems.
m
MDF (Measurement Data Format)
MDF is a file format standardized by ASAM for storing measurement data. It enables the structured storage of signals, time information and metadata. MDF files are widely used in automotive data logging as they efficiently manage large volumes of data and are compatible with common evaluation tools.
Measurement data acquisition (MDE)
Measurement data acquisition refers to the entire process of recording, digitizing, time-stamping and storing physical or digital signals. It includes sensor technology, signal processing, data transmission and data logging. In the automotive environment, MDE is a central basis for the development, validation and safeguarding of vehicle functions.
Modular logger system
A modular logger system is a measuring system consisting of combinable loggers, probes and external memory units. It enables scalable adaptation to different measurement requirements, with the number of interfaces and data rate determining the system configuration.
N
NVH (Noise, Vibration, Harshness)
NVH (Noise, Vibration, Harshness) refers to the entirety of noise and mechanical vibrations in vehicles that are perceived by the occupants. The term is used to evaluate comfort and to analyze the disruptive influences of various vehicle components. Typical sub-areas of NVH are, for example, bumps in the road, squealing brakes or windshield wipers as well as the shaking of the engine.
O
OBD (On-Board Diagnostics)
On-board diagnostics (OBD) is a standardized hardware and software procedure for reading out important vehicle information. The OBD connection is standardized worldwide (e.g. the OBD2 socket). The procedure for reading out fault memories or emission-relevant parameters is standardized and is usually a mandatory requirement for the registration of a vehicle in a country.
OTA Update (Over-the-Air)
OTA (Over-the-Air) refers to the wireless transmission of data, particularly software updates, configuration changes, or parameters, to a device without a physical connection. In the automotive sector, OTA updates are used to update electronic control units (ECUs), infotainment systems, or driver assistance functions during vehicle operation, or to provide new features. This eliminates the need for a workshop visit for many software-related changes.
P
PCAPs (Powercaps)
PowerCAPs (PCAPs) are high-capacity capacitors that can store electrical energy for short periods of time. They are commonly used to bridge voltage drops or to provide a device with power for a short time after the power supply has been switched off.
PLP (Probe Logger Protocol)
PLP (Probe Logger Protocol) is a standardized communication protocol for transmitting measurement data from distributed measurement modules (probes) to a central data sink (logger). It enables time-synchronized data recording between probes and data loggers.
PTP (IEEE 1588)
PTP (Precision Time Protocol, IEEE 1588) is a network protocol for highly accurate time synchronization of devices within an Ethernet network. A Master Clock distributes the reference time to one or more Slave Clocks, which continuously adjust their local clocks accordingly.
R
Raw data
Raw data is unprocessed, originally recorded data in a system-specific or proprietary format. This cannot be interpreted directly without additional information or conversion and must be prepared before evaluation.
RS-232
RS-232 is a standardized serial communication standard for transferring data between devices via point-to-point connections. The data is sent one bit at a time and the interface is used in particular for simple text-based communication.
RSU (Removable Storage Unit)
RSU (Removable Storage Unit) refers to removable data storage units in the XORAYA ecosystem that are used to store and exchange recorded measurement data between the data logger and the evaluation system. They are used in compatible loggers such as the N8000 and N16000.
Real-Time Clock
A real-time clock (RTC) is an electronic clock that keeps track of the current time and date independently of the main processor. It is typically backed by a small battery or capacitor, allowing it to continue running accurately even when the device is powered off.
S
SDV
A Software-Defined Vehicle (SDV) refers to a vehicle concept in which the key functions of the vehicle are controlled primarily by software rather than by fixed, hardwired hardware.
SFP+
SFP+ (Small Form-factor Pluggable Plus) refers to a standardized, pluggable transceiver form factor for high-speed networks with data rates of typically up to 10 Gbit/s.
Signal resolution
Signal resolution refers to the smallest distinguishable change in an analogue signal during digitization and is determined by the number of bits of the analogue-to-digital converter. At 16 bits, 65,536 voltage values can be displayed, which results in a step width of 275 µV at 12 V. The accuracy increases as the number of bits increases.
Signal noise
Signal noise describes the interference of a signal due to unwanted influences from the environment, such as electrical or magnetic fields. If a signal is disturbed to such an extent that it can no longer be restored without errors, it is considered noisy.
SOME/IP
SOME/IP (Scalable service-Oriented MiddlewarE over IP) is a service-oriented communication protocol for Ethernet-based networks in which subscribers subscribe to specific services and data is only transmitted when required. This reduces network traffic compared to cyclical communication.
Voltage consumption
Voltage consumption refers to the electrical voltage required to operate a device and is specified in volts. It must correspond to the specified supply values.
Power consumption
Current consumption refers to the electrical current required by an appliance during operation and is specified in amperes. It depends on the design and power requirement of the appliance.
Synchronization (Time Sync, PTP/gPTP)
Synchronization (Time Sync, PTP, gPTP) refers to the time coordination of several systems in a measurement network so that all recorded data is provided with a uniform time base. This is done via central time sources or standardized procedures such as PTP and gPTP.
T
Probe
A probe is a device for recording and forwarding measurement data to a higher-level system. The data is not stored in the device itself, but on a connected data logger or a data sink. Some systems, such as the XORAYA N4000, can be used both as a data logger and as a probe.
Temperature range
Temperature range refers to the defined range of ambient temperatures in which a product can be operated without faults. In the automotive sector, this is typically wider than for consumer devices, for example from at least -40 °C to +65 °C for X2E GmbH products.
Tisax
TISAX (Trusted Information Security Assessment Exchange) is a standardized assessment and exchange mechanism for information security in the automotive industry. It enables the uniform assessment and recognition of security standards between companies.
Transparency Mode
Transparency Mode refers to an operating mode in which data is forwarded unchanged and without protocol interpretation or content processing. In this mode, the system behaves transparently with respect to the transmitted data and does not interfere with the communication. In measurement and automotive systems, Transparency Mode is often used to record, forward, or tunnel network traffic or bus signals exactly as they are, allowing analysis tools to evaluate the raw data without alteration.
Trigger
A trigger is a defined event to which a data logger responds with a predefined action. A trigger is often used to record received data in a specific time range.
U
UART
UART (Universal Asynchronous Receiver/Transmitter) is a serial communication interface for asynchronous data transmission between electronic devices. It converts parallel data in a micro-controller into serial data streams and vice versa.
V
Vehicle Bus Communication
Vehicle bus communication refers to the communication between electronic control units in vehicles via standardized bus systems such as CAN, LIN, FlexRay or Automotive Ethernet. It enables the exchange of data and control information within the vehicle.
Vehicle Testing
Vehicle testing refers to the systematic testing of a vehicle platform under real and simulated conditions prior to market launch. These tests include road tests, tests of electrical components (e.g. high-voltage battery), NVH tests, tests by national safety authorities (e.g. TÜV or as part of homologation) and virtual test simulations.
Video logging
Video logging refers to the synchronous recording of video data and vehicle data in order to precisely track events over time. Typical applications include recording the instrument cluster or traffic situations for the evaluation of driver assistance systems.
W
Wake
Wake refers to an input of a data logger that is used to activate the device from a low-power state. When a signal is applied, the logger is switched from standby mode to operating mode.
Removable storage
Removable memory refers to an easily removable storage medium that can be removed from a device after data acquisition and read out on an external system. A typical example is the memory card in a digital camera.
X
X2E ASCII
X2E ASCII is a data format for storing logged measurement data in plain text that can be read without special software. Files in this format can be opened with standard editors and typically use the file extension *.dlasc.
X2E Native
X2E Native is a proprietary storage format from X2E for storing measurement data in its original, unprocessed form.
XCP
XCP (Universal Measurement and Calibration Protocol) is a standardized protocol for measuring and calibrating control units that supports various transmission media such as CAN, FlexRay and Automotive Ethernet. It represents a further development of the CCP standard, which is limited to CAN.
XLP
XLP (XORAYA Logger Protocol) is a proprietary communication protocol from X2E for the transmission and processing of measurement data. It enables flexible, device-specific data handling in accordance with the functions of a XORAYA data logger.
Z
Timestamp
Timestamp refers to time information that can be used to clearly determine when data was recorded. It can be available in different formats, for example as milliseconds since the start of measurement or as absolute time information, for example since 01.01.1970.
