Press information To download a text file of this release, a 250 pixel wide low-res image for web use or a 300dpi print quality image, go to www.parkfield.co.uk Onboard IIR Bessel, Butterworth, Chebyshev and Elliptic Filters enhance data acquisition Released 12 October 2001 Microstar Laboratories, specialist manufacturers of PC plug-in DAP data acquisition boards, has announced an IIR filter module, an onboard digital implementation of the five classic filter types: Bessel, Butterworth, Chebyshev, Inverse Chebyshev and Elliptic. The new module, DAPL IFM (IIR Filter Module), is an optional additional command module complementing the existing FIR filters built into DAPL 2000, the 32-bit multitasking real-time operating system that runs on every data acquisition board. DAPL 2000 is normally controlled through Windows (NT, 2000, ME, 98, 95) or Linux, either locally or over a network. DAPL 2000 makes it easy to configure a DAP board for high performance data acquisition applications under Windows or Linux. The onboard operating system supports over 100 easy-to-use commands optimised for data acquisition and control. The new DAPL IFM command module enables a simple means of specifying onboard IIR filters, running in real time and continuously filtering the sampled data stream. A single command, named for the filter type, specifies the filter in just one line, for example CHEBYSHEV(IPIPEO, 8, 0.20, 0.1, $BINOUT) The above command operates on the data stream from channel 0 (input pipe 0), applying an eighth-order CHEBYSHEV filter with a cutoff at 20% of the Nyquist frequency, allowing a 0.1dB passband ripple. It streams the filtered data to the PC through the system binary output pipe, $BINOUT. The other commands, BUTTERWORTH, BESSEL, CHEBYINV, ELLIPTIC, for the four other filter types, have the same simple user interface: source, order, cutoff, ripple level and destination. Any data pipe may act as source or destination. A single DAP board, with external rack-mounted expansion hardware, can handle up to 512 analogue inputs. With the new DAPL IFM (IIR Filter Module), DAP 2000 can now filter the data on any channels using any mix of all five filter types. Each filter operates independently, and different parameters can be set for each. *** Ends: 311 words *** Notes to Editors. The supplied upper picture shows the output from the CHEBYSHEV filter command in the text superimposed on the input waveform, the bottom one shows the FFT of the CHEBYSHEV filter superimposed on the FFT of the input waveform, showing the high frequency attenuation. For further information: Microstar Laboratories contact: Barry Towner Microstar Laboratories UK Limited Meadow Brook Buckland Oxon SN7 8QY tel:+ 44 (0)1367 870184 fax:+ 44 (0)1367 871001 mstarlabs@btinternet.com www.mstarlabs.com Agency contact: Nigel May Parkfield Parkfield House Damerham Hants SP6 3HQ tel: + 44 (0)1725 518321 fax:+ 44 (0)1725 518378 Nigel_May@parkfield.co.uk www.parkfield.co.uk Microstar products make real-time, high-speed data acquisition and control on a PC possible. The company manufactures a range of Data Acquisition Processor (DAP() Boards and systems for PC based data acquisition. The boards have the unique feature of an on-board independent processor, enabling them to work independently from the host PC, free from the delays that are caused by the Windows operating system. Products are available in ISA/PCI format and are compatible with most industry standard software packages. Typical Industry applications are monitoring, test systems, vibration, sound and rotating machinery and process control.