Under the Hood--Extreme: Monitoring Gas Extraction in the Norwegian Sea

The above figure shows an example how the system's buffered ADC acquisition was implemented using LabVIEW Embedded. After setting up the Hardware platform, ADC, FIFO and Serial Ports, two parallel tasks are initiated. The upper task (Timed Loop in LabVIEW, a Thread in VDK's operating system) is "fired" as soon as an ADC buffer has been processed and the analog values are copied to a LabVIEW data structure such as an array.

This data is then fed into a real time FIFO and passed to another loop for further signal processing or data management, like writing to a compact flash card or sending to a terminal.

Key application software functions include:

Main application tasks implemented by Timed Loops / VDK-Threads; Software modularity and re-usability using submodules/sub-VI's; Inter-task data communication by real time FIFO's and global data structures; Application logic based on a classic state machine; An embedded file handler for up to 4GB removable media (CF-Card); Four-channel serial interfaces for acoustic modems and water sensors; Intelligent power and battery management; Shutdown, Wakeup and Watchdog logic; Triaxis accelerometer sensor interface; Measuring of water current, salinity, pressure and temperature; LabVIEW Embedded Module for ADI Blackfin Library.

One of Schmid Engineering's part was the development of all necessary board functions, device driver VI's and additional operating system services to realize reliable, deterministic real time behaviour on the basis of the LabVIEW Embedded Module for ADI Blackfin.

The library functions include : Board initialisation, shut down and wake up, RTC programming, power management, watchdog, ADC, DIO, Serial IO, Removable Media (CF), GPIO, Timer and Flash programming. Schmid Engineerings firmware engineers tweaked the embedded operating system VDK to help realising synchronized data sampling of all CSP's, in fact the system's core function :

All CSP's start triggered sampling with an accuracy of maximum 100us jitter.

Each MSP's and CSP's clock stability is less then 1ms/30min.

The acoustic modems propagation delays and any software latencies are fully compensated.

This project served as a real life test bench for Schmid Engineering's latest product "Zbrain BSP for LabVIEW". Thanks to the valuable ideas, suggestions and test feedback from NAXYS AS, the Board Support Package (BSP) continuously matured in the shortest of times. Embedded system engineers now can gain from serious, productive graphical embedded system design.

Embedded Hardware Solution

Both MSP and CSP hardware rely on the Embedded Zbrain System Toolbox supplied by Schmid Engineering AG, a swiss solution provider for embedded systems. This modular solution is based on Analog Devices' Blackfin processor by and programmed using National Instruments "LabVIEW Embedded Module for ADI Blackfin". The low power, mixed signal board ZMobile serves as the main platform for the pipeline monitoring system.

This off-the-shelf solution provided all required hardware functions for DeepBlue:

High Computing DSP Power

Dynamic Energy Management

Smart Battery functions

Onboard RTC and Watchdog

Analog IO for triaxis accelerometer

Digital IO for trigger impulse

Serial IO (acoustic modems)

Removable Media (data storage)

The final element is an Expansion Board Connector for a custom specific IO and Controller Board. Most of the functionality was already provided by Zmobile. A custom specific add-on board completed all missing circuits, connectors and interfaces. This two board approach and combination of standard and customer solution saved precious engineering time and lowered project risks.