Introduction to OWL Data Loggers 5
© 2001 ... ACR Systems Inc.
1.3 How OWL Data Loggers Take Readings
OWL Data Loggers canstore 32,767 readings.Once thememory is full, theOWL can be setup to
either bump the oldest reading to make roomfor the newest (sliding window of 32,767 readings) or
stop recording.
You can set the frequency at which your logger takes readings through the software. At a sample rate
of eight seconds, one reading is taken everyeight seconds and saved to memory. As you slowthe
sample rate the logger begins to average readings before savingthem to memory. To do this the
logger takes a reading every eight seconds, but insteadof transferring this directly to the logger's
memory, it stores the readings ina buffer (a temporary memory) where it is retained untilthe sampling
interval is over.
When you backup a logger's data onto yourcomputer, thecorrect timeand date are referenced to
each reading. All readings are then individually time and date stamped and processed by an equation
associated with the data logger channel. The result is a collection of accurate time-based data ready
for detailedgraphingand analysis.
1.4 How to use OWL Data Loggers
Using your OWL Data Logger for most applicationsis a simple process. With proper planning, setup,
installation and retrieval of your data logger, you can beassured that the information you collect will be
both correct and useful. This section providesgeneral procedures for using OWL Data Loggers. For
additional and specific information on these steps, refer to the chapter in this manual that deals with
the particularOWL model you have.
How to Communicate
In order to setup or get your logged data, youmust interface theOWL with thePC. The software
section of this reference guide explains in detail how to configureyour PC's communication port with
your LIC-101 Interface Cable. The LIC-101 can beeither plugged into or pointed at thelogger's optical
port in order to send a setup or retrieve loggeddata.
Planning
Proper planning is the key to successful data logging. Time spent in this stage willhelp you save time
and frustration later.To helpyou plan, answer these questions:
What exactly do Iwant to measure?
Where is the bestplace to measure?
How long do I wantto monitor for?
Should other variables be monitored simultaneously?
Setup
To setup your OWL Data Logger you must first have TrendReader Software installed and running on
your computer. You can then configure your logger with various software setup options.
*see figure1, next page
Set Sampling Rate
Always confirm thesampling rate (how often the logger takes readings) to make sure it will be
acceptable for your application. You canalter the frequencyat which your OWL Data Logger records
readings by double clicking your mouse on thecom port icon, pointingthe wandat the logger, and
select Setup,Sample Rate inTrendReader Software. You maychoose any valuebetween 8 seconds
and 34 minutes in4 second increments. The menu gives youthe number of seconds to enter for the
most common intervals: 8 seconds, 20seconds, 1 minute, 2 minutes, 5 minutes, 10minutes and 30
minutes. In fast read mode intervals between 0.2 and 10 seconds may be chosen.
To helpdetermine which sampling rate youshould choose,answer these questions:
