AAF-3 2- to 8-Channel Anti-Alias Low-Pass Filter and Instrumentation Amplifier Card for Signal Conditioning in Data Acquisition Systems

AAF-3

2- to 8-Channel Anti-Alias Low-Pass Filter and Instrumentation Amplifier Card for Signal Conditioning in Data Acquisition Systems

With Band-Pass Filter Options!

Features

Compatible with any A/D converter board
Modular design allows any combination of 2, 4, 6, or 8 programmable anti-alias low-pass filter and/or differential instrumentation amplifier channels per card for front-end signal conditioning
Unlimited number of boards per system
Software selectable individual channel gain steps of 0.5, 1, 2, 5, 10, 20, 50, 100, 200, 500, and 1000 using the AAF-3G
Use the AAF-3F to software select between 8-pole elliptic to 100kHz or linear phase to 50kHz filter characteristics
Use the AAF-2Fe for 8-pole filter characteristics of:

Bessel to 66kHz maximum corner frequency

Butterworth to 100kHz maximum corner frequency

Cauer/Elliptic to 50kHz maximum corner frequency

Cauer/Elliptic to 100kHz maximum corner frequency

Linear Phase to 100kHz maximum corner frequency

Linear Phase to 200kHz maximum corner frequency

Up to 4 channels of Band-Pass Filtering per board when the low pass filter is combined with the AAF-HP high pass filter.
Software select any corner frequencies from 1 Hz to the maximum corner frequency with no steps
Corner frequencies may be controlled with an external clock for tracking filter applications
Up to 4 different corner frequencies can be applied to any channel pair.
Software controllable synchronization of the internal filter-clock to the A/D sampling rate to eliminate sampling errors
Shipped with programs and libraries for Windows XP,NT,2000,Me,98,95
Subroutine Library Compatible with LabVIEW, HP-VEE, C/C++, VisualBASIC, Delphi, and more.

Overview

The AAF-3 is a 2- to 8-channel anti-alias low-pass filter and instrumentation amplifier ISA bus plug-in board for front-end signal conditioning in PC-based data acquisition systems. It provides a choice of 8-pole Butterworth, Bessel, Elliptic(Cauer) and linear phase linear phase characteristics to meet specific application requirements.

Each channel on the AAF-3 can have its own instrumentation amplifier with differential inputs. Each channel can be independently programmed for a gain of 0.5, 1, 2, 5, 10, 20, 50, 100, 200, 500 or 1000 giving the AAF-3 an input range capability of 5mV to 20V.

The corner frequency of each 2-channel filter module can be set with an external clock or programmed with one of the two internal clock sources for a range of frequencies from below 1 Hz to 200 kHz. Each 2-channel pair can operate with a different corner frequency, allowing for up to 4 different corner frequencies on each AAF-3.

The input can be wired single-ended or differential. If differential input is required, the AAF-3G must be used as a front end to the AAF-3F filter module or the AAF-2Fe may be used with or without the AAF-3G.

Band-Pass Filter Options

The AAF-3 can be configured as a band-pass filter by using an AAF-HP high pass filter in series with an AAF-2Fe or AAF-3F low pass filter module. This configuration can be made with the AAF-3M-001 factory installed option or the channel series configuration can be made in the external cabling. The filter sections offer a maximum pass band bandwidth of 200:1. For example, a filter with a high pass or lower corner frequency of 1Hz can have a maximum low pass corner frequency of 200Hz.

Support Software

Alligator Technologies has developed both DOS and Windows based menu-driven and an application program interface (API) DLL library for controlling the functions on the AAF-3. We support both of the Windows 95 and Windows NT device driver configurations making the AAF-3 software compatible to any version of 32-bit Windows and any other operating system supporting the Windows constructs. The operating system is sensed automatically and the proper device driver will operate without user intervention.

Menu-Driven Software - The AAF-3 is supplied with SystemViewAAF for Windows and the menu-driven SETAAF3 for DOS, both of which control the Gain, Filter Type, Clock Source, and Actual Cutoff Frequency. Pictured is the software control dialog for the AAF-3. The control of the AAF-3 is straight forward and intuitive. To obtain the gain, filter type or clock source use the pull down menus. To set the corner frequency, type any corner frequency within the bandwidth limits of the filter in to the edit field. Simply click Apply to send the parameters to the board. In systems where more than one AAF-3 is installed each board can be set with one or multiple dialogs open simultaneously. The multiple parameter configurations can be saved for later retrieval.

Function Libraries- Many applications require direct control over multiple devices in the system. We make the application program interface (API) to the DLL available for applications requiring control written in any high level language so that control of the AAF-3 can be tightly integrated with other device controls.

Example application programs are provided for popular compilers, including Visual C++, Visual Basic, Borland C++, and Borland Pascal.

LabVIEW Driver - AAF3.LLB VI can be graphically assembled with other VIs in a LabVIEW block diagram to create a complete instrumentation system.

HP VEE User-Object - Both 16- and 32-bit user-objects for HP VEE.

Connection to Your Data Acquisition System

All I/O connections from the AAF-3 are made via two 26-pin female high-density D-sub connectors that extend out of the rear of the computer.

Screw Terminal Card - The STA-AAF-3 screw termination board provides labeled one-to-one I/O connections for the AAF-3. The STA-AAF-3 uses Wago connection points, a spring clamping system that reduces wiring time substantially compared to screw-type methods. The clamping force adjusts automatically to wire size, so it provides a reliable contact virtually independent of operator skill. The end-result is secure, vibration-proof, maintenance-free clamping every time.

Cable Accessories - A variety of custom cable accessories are available for connecting the AAF-3 to any A/D board and to any system. These accessories include BNC connector boxes for input and twisted-pair ribbon cables for output.

How to Order

AAF-3 - Programmable low-pass filter and instrumentation amplifier card for the PC
Filter and gain channels are available in increments of 2 channels. The following are some examples:
- AAF-3/2G2 - 2 filter channels, 2 gain channels
- AAF-3/8G8 - 8 filter channels, 8 gain channels
- AAF-3/4G0 - 4 filter channels only
Accessories -
- CA33-x-y - Twisted-pair ribbon cable for connecting AAF-3 output to any A/D card (input only), specify length (x) in 1/4 meter increments and A/D card (y)
- CA39-x-y-z - Twisted-pair ribbon cable for connecting AAF-3 output to any A/D card with single I/O connector and A/D outputs are required, specify also A/D-output connector source (z)
- AT-BNC-3/I - Standard BNC connector box for AAF-3 input
- AT-BNC-3/O - Standard BNC connector box for AAF-3 output
- STA-AAF-3 - Screw terminal panel for the AAF-3
  - CAT-A3-I - Shielded cable for connecting AAF-3 input to STA-AAF-3, 0.5m
  - CAT-A3-0 - Shielded cable for connecting AAF-3 output to STA-AAF-3, 0.5m

Related Pages

Simplify your system connections. Check out our list of Cable Accessories.
Need help selecting the best filter type for your application? Check out our Filter Type Selection Guide.
What is aliasing and how do filters eliminate its effects to ensure more accurate results? Find out in our Low-Pass Filter Tutorial.

PHONE 949-515-1400 FAX 949-515-4724 E-MAIL productinfo@alligatortech.com