D-EL-6003Bj
05. 2009 AG
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ECOLOG-NET
5. Defining the threshold values and alarm parameters
Threshold values and alarm parameters are defined in window "Setup of Alarm Parameters". Threshold
monitoring is only performed at sensors which are selected in the measurement function
.
The following conditions trigger an alarm:
- The measured value must lie outside the defined range; i.e. the measured value is higher than the
maximum allowable threshold value or lower than the minimum allowable threshold value.
- The threshold violation must exceed the defined alarm delay times.
The threshold violation remains active until the measured value reaches the allowable range again.
- The Hysteresis parameter is used for controlling external processes (P-Controller).
Set 0 for alarm functions with time delay.
- Example: a) Alarm function with time delay: Hysteresis = 0°C
b) Control function with P-control character: Hysteresis = 1°C
Alarm on
Activate this checkbox to switch on the alarm threshold function,
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Chapter 2.8
Alarm Thresholds
Data enter fields for the lower and upper threshold values.
Hysteresis
The hysteresis is used to prevent "fluttering" (uncontrolled on/off switching) at the alarm contact.
To change the state of the contact, the deviation of the measured value from the threshold value
must exceed the value defined at the Hysteresis enter field.
Alarm delay
- normal
time
An alarm is not triggered until the length of threshold violation has exceeded the specified time.
- defrost on
If the "Check defrost" function is active and the defrost contact D1 is closed, then an alarm is not
triggered until the length of threshold violation has exceeded the time specified at this enter field.
Alarm Output
This function is used for all applications where the alarm contact controls an external device such
as a flash light or a telephone dialing unit.
- no selection made
The alarm contact is closed
for the duration
of the threshold violation.
- self-sustaining
This mode is used for all applications where the alarm contact controls an external device such
as a flash or a telephone dialing unit.
The following text is displayed until a
manual reset
is executed: ALARM.
The alarm contact remains closed until a
manual reset
is executed.
- using CRA bracket (...H2 only)
This bracket is not available
- buzzer
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Chapter 2.10
Close / Reprogram / Print Status
These buttons are used to program the datalogger, to print out the current status (...H2 only)
and to close the "Setup of Alarm Parameters" window. At the ...P4 datalogger, a status printout
can be made with function: Print.
Manual
Hysteresis
Threshold
Threshold understepping
Threshold overstepping
Hysteresis
Threshold
Threshold over/understepping
Measured values inside alarm threshold
Alarm delay time
Alarm