Crystal DataLoggerXP - Manual (Page 5)

Page  • DataLogger
XP
User’s Manual
Note: An evaluation mode allows up to 00 data points to be taken after which authorization
is required. For unlimited operation, the gauge must be authorized for use as a data logger.
The gauge can be authorized either by the factory, prior to shipment, or in the field, by the
use of an authorization key. Gauges are always shipped from the factory in standard mode.
Datalogger.Terminology
The XP2i stores data in memory. Memory is expressed in terms of bytes available, with each data
point taking some number of bytes to store. A clear gauge (one without any data in memory) will
have approximately 8,000 bytes available. How long a gauge can log data depends on several fac-
tors, each of which is described below.
The first factor is the logging interval. This is the time, in seconds, between each data point.
The second factor is the logging type. The logging type controls what kind of data is stored for
each reading, with different modes requiring different amounts of memory for each reading.
The third factor is the dynamics of the input pressure. Data is compressed into memory when-
ever possible. Therefore, pressure that is changing slowly over time will require less memory as
compared to large variations of input pressure. More information on how these factors affect the
maximum number of readings can be found under “Maximum Number of Readings” on page 9.
Together, the logging interval and logging type are referred to in this document as the logging
parameters. Logging parameters can be set up one of two ways: on a computer connected to an
XP2i, or on an XP2i by itself. This second option allows the user to make changes in the logging
parameters while in the field.
Once the logging parameters have been selected, the gauge can begin sampling data. A set of
one or more readings taken by the gauge is called a run. The user can specify different logging pa-
rameters for each successive run. There is no limit to the number of runs a gauge can store, provid-
ing there is sufficient memory to store them.
After one or more runs have been stored on the gauge, DataLoggerXP can download the data to a
computer for viewing and/or saving to the computer’s hard drive. This is done by simply connect-
ing the gauge to the computer via a serial cable and using the Download function of the applica-
tion software.
Once the data is downloaded to the computer, you will typically clear the gauge. This removes
any existing runs from the gauge’s memory, so that all of the memory is available for the next
sequence of runs.
Typical.Usage
While there are a variety of ways in which the DataLogger software and XP2i digital test gauge can
be used, a typical way to use the Datalogger might be like this:
1 You set up the logging parameters—either on the computer or directly on the XP2i keypad—
and start recording data.