Bellevue, Wash.If your data-acq application needs realtime processing, yet you typically run engineering applications on a Windows platform, check out Microstar Laboratories's latest DAP (Data Acquisition Processor). The company's mid-range plug-in provides concurrent processing in order to achieve deterministic acquisition on a PC.
Microstar Laboratories's latest mid-range DAP board, dubbed the DAP5000a/526, clocks its own on-board Intel Pentium 233-MHz processor. The board also includes 32-Mbytes of DRAM, and has sufficient horsepower to run many DSP routines.
This DAP board, and others from Microstar, supports its additional processor by running a dedicated realtime operating system called DAPL that you control from a Windows application. This extra resource is what frees your application from system delays.
For its part, the board's Pentium handles realtime processing with low latency (0.1-ms task time). The board also ensures continuous gap-free I/O. What's more, I/O speeds are individually software-selectable.
The less-than-$3200 DAP 5000a/526 provides 16 analog inputs, two analog outputs, 16 digital inputs, and 16 digital outputs. External rack-mounted hardware can extend these channel counts to as many as 1024 channels.
On-board circuitry and a special synchronization connector also support multiple DAP5000a boards running in the same PC. In fact, any mix of MicroStar's DAP models can be socketed in your desktop PC's card cage.
In multi-card systems, a software-selectable master DAP provides a sampling clock, or an update clock, to software-selectable slave DAPs. Beyond that, other hardware and software options can sync multiple DAPs distributed over a network.
A DAP 5000a can also automatically generate external expansion control signals; your PC isn't involved. Any channel is referred to by number. There's no load on the PC, even at maximum speed. Very nifty!
DMA For Speed
Back to a single DAP 5000a. Any one DAP 5000a requires only a single PCI bus slot. It uses DMA (direct memory access) bus-mastering for high-speed data transfer to your PC.
In operation, one of these boards can acquire 14-bit data at up to 800-ksamples/s, and can convert 833,000-values/s on each of its two on-board analog outputs.
Channel numbers and gain settings, and the choice between single-ended or differential inputs, are all programmable. Each setting can be changed on a channel-by-channel basis.
High-speed synchronous updates and fast-response asynchronous updates are both possible, too. Both on-board analog outputs can also be updated concurrently. Synchronous outputs can be configured to run continuously, to stop after a set number of updates, or to send output data in pre-defined bursts.
The system's clocks and triggers are TTL-compatible. And, on-board circuitry protects against signals that violate timing requirements. Channel list clocking also permits all input channels to be acquired on a single external clock edge.
DAPL Supports Conceptual Pipes
In use, digital data streams through so-called conceptual pipes on the board that you set up using DAPstudio, a less-than-$200 Windows application. The onboard processor performs any required operations as it transfers data from pipe to pipe.
Using DAPstudio, you choose these onboard operations from more than 100 commands available in DAPL (a typical application may require six or seven of them). The commands issued to DAPL determine which low-level tasks DAP will perform, and how it will respond with control signals. The commands configure the DAP for the application.
Click To Configure
DAPstudio lets you specify DAPL commands by clicking on appropriate tools as you design your system. It then lets you save the working configuration as a DAP application. At each step in the development process, the next step presents itself.
At the end of a DAPstudio session you've also automatically produced documentation that defines your application. You then can use DAPstudio to run your applicationfrom any PC on a networkwith no custom programming or other software.
Although DAPstudio lets you configure and control any DAP without any other Windows software, you can also do this from National Instruments LabVIEW, The Mathworks MATLAB, and other third-party software. You can also use C++, VisualBASIC, and other applications that support DLL (dynamic link library) calls.
Microstar Laboratories also provides freebie unrestricted versions of both hardware and software. You can download a full version of DAPstudio from Microstar's Web site.
Click here for a table of specs and additional information, as well as links to related products and accessories.
For more information, contact Microstar Laboratories, Inc., 2265 116th Ave. NE, Bellevue, Wash. 98004. Phone: 425-453-2345. E-mail: firstname.lastname@example.org
Microstar Laboratories, 425-453-2345, www.mstarlabs.com