Command Modules: Gateway to Onboard Processing
DAPL commands: pre-built, or make your own
No matter how many processing commands the DAPL system supports, the one special function you really need might not be there. And that is why DAPL processing is extensible by design.
This page lists available modules, from the most basic to the most specialized. If you don't see what you want here, or if you are already sure that your requirements are unique and require a unique solution, check the Developer's Toolkit for DAPL pages to learn about building your own command modules.
General utility modules – included with each xDAP or DAP system
These modules are provided and installed by default with all editions of the DAPtools Software. They are loaded automatically each time your host system boots up.
- DAPLCMDS, DCMDS3 — general-purpose commands
- Though these are actually loaded into the DAPL system separately, they are used so often that they are considered built-in: all of the common operations
SKIP, COPY, MERGE, AVERAGE,and so on.
Extended utility modules – included with each DAPtools Standard add-on purchase, used with xDAP or DAP systems
These modules provide advanced options that might be needed for certain kinds of applications. The DAPtools Standard software editions will install these automatically.
- WSM — sine wave synchronization
- The Wave Synchronization Module provides capabilities similar to the Time Base Synchronization Module, producing arbitrary sampling rates based on a reference timing signal that is a continuous sine wave rather than a digital pulse sequence. It can use waveforms with or without synchronization to a global time standard. While stable sine wave oscillators work the best, this module also works robustly with relatively bad timing sources such as an AC power main waveform.
- TBTSM — time base synchronization
- The Time Base Synchronization Module provides a modern, DSP-based approach to obtaining time-aligned sampled data sets from multiple measurement stations, referenced to a common digital timing signal such as GPS or IRIG-B. Hardware-only solutions to achieve similar ends can be complicated and expensive. This package uses smarter processing compatible with relatively simple hardware.
- AAMM — digital anti-alias filtering
- The Anti-Aliasing Multichannel Module implements self-configuring, all-digital anti-aliasing filtering that can simplify measurement systems, deliver superior sampling results, and avoid the cost and complexity of hardware-based anti-alias filters.
- ROTM — sampling extensions for rotating machines
- The Rotating Machinery Analysis Module provides advanced sampling techniques combining time-referenced sampling with rotary-encoder-referenced sampling, for the best features of both. Sample at extended angular resolution, find corresponding events in angle-dependent and time-dependent data streams, track instantaneous rotation speed, etc.
- DAPLIFM — IIR filtering commands
- When you are required to use traditional filter designs based on classical analog filters — for example, the famous Butterworth filters — this module provides accurate, efficient, and easy to use IIR filtering commands for these familiar filter families.
The "Specialty" modules – available online, but require use of an xDAP or DAP system
These are available for download from the Web site, but do require access to xDAP or DAP hardware systems.
- SENSORM — sensor interfacing module
- The sensors module provides additional support for calibrated "linearization" corrections yielding best possible physical measurements from conversions of sensor voltage readings. While mainly intended for nonlinear temperature sensors, some of the commands in this collection are more general.
- MTSFILTM — alignment of data in time
- The Multi-Channel Time Shift Filtering Module provides a new capability: to take multiple-channel data captured in rapid succession and align the values in time, producing data sets indistinguishable from those with all channels captured simultaneously. You get the predictable phase alignment at a fraction of the price of simultaneous sampling hardware. This extends to DAPL 2000 systems (for DAP boards) a capability of the DAPL 3000 system (for xDAP systems).
- THIRDOCTM — spectrum analysis by octaves
- Frequency bands are perceived as approximately equal if they organized as octaves, with each band twice the width of the band immediately below it. However, this geometric spacing is inconsistent with the linear spacing of frequencies in a normal FFT frequency analysis. The 1/3 Octave Analysis Module takes advantage of unique properties of radix-12 FFTs to analyze geometrically-spaced 1/3 octave bands as defined by audio standards.
- IEC651M — hearing sensitivity corrections
- The IEC651 A-Weight Audio Filtering Software provides a standard-defined A-weight correction to a signal prior to further other octave, power spectrum, or FFT analysis, so that the frequencies with highest degree of audibility have the highest impact on the analysis. Typically, this is used in environmental noise measurement applications.
- GOERTZ — frequency detection
- The Goertzel filtering module provides a filter-based method for detecting a single frequency efficiently and with very high selectivity using a slightly modified version of the classic Goertzel algorithm.
- Additional experimental modules — various
- These explore very specialized topics in feedback controls and digital signal processing. Follow the links to the application stories that describe them. These might be useful if you are faced with similar challenges and you not sure where to start.