Casella CEL Sensus data logger unit - Manual (Page 13)

3. COMMANDS
A full and detailed description of all the commands available on the Sensus
Logger is beyond the scope of this handbook. When this information is
essential to your particular application, please contact Casella CEL and
request a copy of the document: “Sensus - A Programmers Guide” (HB3291).
3.1 Data Channels
The configuration information stored in a data channel controls how input
data is collected, processed and stored by the logger.
3.1.1 Channel Type
The channel type allocated to a data channel controls where the channel will
go in order to obtain real world measurements.
Allowable channel types are detailed below.
Data Channel Type Function
Analog Readings are taken from analog input
signals (differential or single-ended).
Counter Readings are taken from digital counter
inputs.
Data Readings are taken from other data
channels.
Instrument Readings taken from RS232 Inst. interface
Passive This data channel type does not obtain
readings itself, rather it waits to be
updated from other sources (for example
alarms).
Parameter Allows values held in the logger’s
parameter space (system variables) to be
processed just like other data.
Options and settings that differ depending on the channel type selected will
be explained in greater detail in Section 2.2, Type Specific Configuration. The
following paragraphs describe options that are common to all channel types.
3.1.2 Description
The text allocated to the data channel’s description tells the user the physical
property actually being measured by the channel. The text is used to identify
the channel contents in alarm messages and other outputs.
3.1.3 Units
This text identifies the measuring units used when presenting data for the
channel. This is used in alarm messages, logging to CompactFlash™ cards
and LCD messages.
3.1.4 Display Format Specifier
The text allocated to this parameter controls how data values for the channel
are presented to the user. This specifier controls whether a value is signed,
the field width and the number of decimal places. Character positions are
indicated by the hash ( # ) or zero ( 0 ) characters. Some format specifier
examples are given below.
Commands SENSUS Digital Data Logger -
Users Handbook
Page 13 of 44