Overview; Operations; Programs; Sensors - Campbell CR300 Series Product Manual

1.1.2 Overview

The CR300 series data logger is the main part of a data acquisition system (see CR300 series data
acquisition system components (p. 1) for more information). It has a central-processing unit
(CPU), analog and digital measurement inputs, analog and digital outputs, and memory. An
operating system (firmware) coordinates the functions of these parts in conjunction with the
onboard clock and the CRBasic application program.
The CR300 series can simultaneously provide measurement and communications functions. Low
power consumption allows the data logger to operate for extended time on a battery recharged
with a solar panel, eliminating the need for ac power. The CR300 series temporarily suspends
operations when primary power drops below 9.6 V, reducing the possibility of inaccurate
measurements.

1.1.3 Operations

The CR300 series measures almost any sensor with an electrical response, drives direct
communications and telecommunications, reduces data to statistical values, performs
calculations, and controls external devices. After measurements are made, data is stored in
onboard, nonvolatile memory. Because most applications do not require that every measurement
be recorded, the program usually combines several measurements into computational or
statistical summaries, such as averages and standard deviations.

1.1.4 Programs

A program directs the data logger on how and when sensors are measured, calculations are
made, data is stored, and devices are controlled. The application program for the CR300 series is
written in CRBasic, a programming language that includes measurement, data processing, and
analysis routines, as well as the standard BASIC instruction set. For simple applications, Short Cut,
a user-friendly program generator, can be used to generate the program. For more demanding
programs, use the full featured CRBasic Editor.
If you are programming with CRBasic, you can use the extensive help available within the
CRBasic Editor (also see https://help.campbellsci.com/CRBasic/CR300/ for searchable, CRBasic
online help).

1.2 Sensors

Sensors transduce phenomena into measurable electrical forms by modulating voltage, current,
resistance, status, or pulse output signals. Suitable sensors do this with accuracy and precision.
Smart sensors have internal measurement and processing components and simply output a
digital value in binary, hexadecimal, or ASCII character form.
1. CR300 series data acquisition system components 3