7 Configuration
64
An alarm may be caused by:
• Partial or total failure of heating elements or other parts in the control loop
• Reversal of the control direction (for example, "direct" instead of "inverse")
Functional limitations
The control loop monitoring is not active in the following cases:
• Autotuning active
• Manual mode
• Output level is not at its maximum limit (heating mode) or minimum limit (cooling mode)
Parameter dimensioning
The controller parameters must be optimally adjusted for the control loop monitoring to function correctly,
e.g. using autotuning. If alarms occur temporarily, despite the plant operating correctly, either the re-
sponse time must be increased, or the monitoring band must be narrowed. To do this, plot the ap-
proach curve, e.g. with the startup function of the setup program.
7.9.5 Output level monitoring (setup only)
Output level monitoring monitors the output level in the corrected state. The output level must be within
a definable range around a mean output level. If it is not, an alarm is issued.
x
y
t1
T
A
Actual value
Output level
Start of monitoring
Alarm period
Δx
y
M
T
R
t2
Monitoring band
Max. output level (for example, 100 %)
Response time
End of monitoring
Parameter Selection/text/value Description
Function Off Output level monitoring is not active.
On Output level monitoring is active.
Determination time 0 to 9999 (350) Calculation time (in seconds) for the mean output
level