Campbell Scientific PC400 Datalogger Support Software - Manual (Page 218)

Appendix A. Glossary of Terms
Intermediate Storage – Datalogger memory used to temporarily store values
(such as a running total and number of samples for an average calculation),
typically to be used for output calculations. The datalogger uses Intermediate
Storage to accumulate sensor readings until output.
L
Link – Communications route between two devices, for example the phone
link between two phone modems.
LDEP – Logger Data Export Protocol, a protocol and client application that
provides for data distribution from the communications server to a third party
application through a standard TCP/IP socket. Installed with LoggerNet
Admin; see the associated PDF file for more information. Requires record-
specific acknowledgements for record flow control. See LDMP.
LDMP – Logger Data Monitoring Protocol, a protocol and client application
that provides for data distribution from the communications server to a third
party application through a standard TCP/IP socket. Installed with LoggerNet
Admin; see the associated PDF file for more information. Requires very simple
acknowledgements for record flow control. See LDEP.
Log Files – Text files that are stored on the computer’s hard drive that record
activity. They contain information about communications between the
communications server and other devices in the datalogger network. Log files
are typically used for troubleshooting purposes. LoggerNet has four types of
log files: Transaction, Communications Status, Object State, and Low Level
I/O. Refer to Appendix C, Log Files and the LogTool Application, or the help
within the LogTool (in PC400 click the Tools | LogTool menu item)
application for information on these log files.
M
MD9 – An MD9, or multi-drop modem, is a communications device that uses
twisted pair cable for connection. Typically, the system consists of one MD9
base modem that is attached to the user’s computer, with one or more remote
modems at the datalogger field site. One remote modem is needed for each
datalogger at the field site.
Measurements – Values stored by the datalogger in an Input Location after
reading an electronic signal from a sensor and converting the raw signal into
meaningful units.
Mixed-array – Dataloggers with mixed-array operating systems save output in
a common area of the datalogger’s final storage memory. When data is directed
to final storage, a unique array ID number is stored, followed by other values
as determined by the datalogger program. These are called “elements”.
“Mixed-array dataloggers” typically save all information that is directed to
output storage to the same area of datalogger memory (as opposed to table-
based dataloggers that always store different output processing intervals to
separate tables in datalogger memory). Data retrieved by the PC must be
processed by PC software to separate the data based on the array IDs.
Modem – From “modulator-demodulator”; a device used to transmit and
receive digital data over normally analog communications lines, such as an
audio signal on telephone circuits. A modem attached to a computer performs
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