Casella CEL Sensus data logger unit - Manual (Page 30)

8. ALARMS
The Sensus Logger includes a comprehensive set of rules that can be used
individually or in combination to detect alarm conditions. These alarm
conditions can then cause one or more actions to be taken by the logger.
These actions include an audible warning, external alarm triggering, changing
the logging rate and remote message transmission via modem and SMS.
Each of the 16 alarm channels can be programmed in isolation or
combined for greater flexibility. The following sections describe how each
parameter of these alarms work and how it can be programmed
8.1 ID Text
Each alarm can be allocated a piece of descriptive text, which gets
transmitted during remote message and SMS alarm conditions. This text can
be used to identify the particular alarm causing the transmission when more
than one alarm is active on the logger.
In addition, each remote message is also prefixed with the logger’s own ID
text and ID number allowing immediate or automatic identification of the
alarm source at the receiving end.
8.2 Input Channel
Each alarm channel monitors a single input data source and processes the
value of this data against its own set of rules. The data source can be any
one of the available data channels, analog, counter or calculated. Irrespective
of channel type, the alarms work solely on its current value.
8.3 Test Mode
This describes the logical comparison to be applied by the alarm to its
selected data value. The logical result of this comparison will determine
whether the alarm condition is active or not.
The available test modes are listed below.
Alarm Test mode
Mode Result,
none Alarm always returns false,
eq Alarm true if data value equals limit value,
neq Alarm true if data value not equal to limit
value,
gt Alarm true if data value greater than limit
value,
lt Alarm true if data value less than limit
value,
lt or gt Alarm true if data value less than first
limit value or greater than second limit
value,
gt and lt Alarm true if data value greater than first
limit value and less than second limit
value.
Alarms
Page 30 of 44
SENSUS Digital Data Logger -
Users Handbook