A Technical Aspects; How Does It Work - ADInstruments PowerLab/4SP Owner's Manual

A P P E N D I X A
A
Technical Aspects
This appendix describes some of the important technical aspects of
the PowerLab/4 , PowerLab/8 , and PowerLab/16 , to give some
SP SP SP
insight into how they work. You do not need to know the material
here to use your PowerLab. It is likely to be of especial interest to the
technically minded, indicating what the PowerLab can and cannot
do, and its suitability for particular purposes. You should not use it as
a service manual: remember that user modification of the PowerLab
voids your rights under warranty.

How Does it Work?

The PowerLab is essentially a smart peripheral device specifically
designed to perform the various functions needed for data
acquisition, signal conditioning, and pre-processing. It contains its
own microprocessor, memory, and specialised analog amplifiers for
signal conditioning. The block diagrams in Figure A–1, Figure A–2,
and Figure A–3 show the essential elements of each PowerLab.
All sampling, output, and communication functions are controlled by
an internal 32-bit, 68340 microprocessor running at 16 MHz (16
million cycles per second). This CPU (central processing unit) has
access to 512 kilobytes of RAM (random access memory) for data
storage and buffering prior to transmission to the computer. The
PowerLab makes use of FIFO (first in, first out) memory devices,
which provide a temporary storage area for both analog input and
analog output signals. These storage areas help increase the
processing capacity of the hardware by relieving the load on the
PowerLab microprocessor.
PowerLab Owner's Guide 27