User's Manual

File : CS-SUP-MUTI-WTHERMSPETEC-E02.sxw
5.6 MANAGEMENT OF THRESHOLD ALARMS
The WaveTherm module detects when the values exceed the threshold levels (high or low) for a given period
of time.
The WaveTherm – PT100 and PT1000 may be configured with a precision level offering a more reliable
measurement even in environments with excessive interference (see chapter 5.1.1).
Three types of threshold alarm detection methods may be programmed :
 immediate threshold alarm detection
 threshold alarm detection for a given continuous period of time (successive mode)
 threshold alarm detection for a total period of time (cumulative mode)
5.6.1 THRESHOLD ALARM DETECTION
Threshold alarm detection requires periodic measurement of the temperature for a predefined period. The
value of this period enables establishment of the threshold alarm detection reactivity.
This period is set independent of the datalogging period. However, for power saving reasons, it is
recommendable to set the datalogging period as a multiple of the threshold alarm detection period.
The following parameters apply to this function:
 High threshold alarm,
 Low threshold alarm,
 Threshold excess time (used in cumulative and successive mode),
 Mode parameter setting byte (high threshold enabled, low threshold enabled, immediate,
successive or cumulative mode).
➢ In cumulative mode, an alarm is detected when the total temperature threshold alarm time is higher than
the set duration parameter.
With a threshold excess duration, t
seuil
= 10 measurement periods, one gets t
1
+ t
2
+ t
3
+ t
4
> t
seuil
WaveTherm module technical specifications page 28 of 31
High
threshold
t
1
t
2
t
3
t
4
Alarm
Measurement period