JUMO 705010 mTRON T - Multichannel Controller Module Operating Manual - Manual (Page 84)

6 Configuration
84
If the actual value does not leave the monitoring band within this timeframe, an alarm signal is
generated. The alarm signal is maintained for as long as the maximum or minimum output level
is produced and the actual value is within the monitoring band.
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 (e.g. "cooling" instead of "heating")
Functional limitations
The control loop monitoring is not active in the following cases:
•
Self-optimization 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 self-optimization. If alarms occur temporarily, despite the plant operating
correctly, either the response time must be increased, or the monitoring band must be nar-
rowed. To do this, plot the approach curve, e.g. with the recording function of the multifunction
panel or with the startup function of the setup program.
t
t
x
y
Dx
x
y
M
y
T
R
T
A
t1 t2
x Actual value
x Monitoring band
y Output level y
M
Max. output level (e.g. 100 %)
t1 Start of monitoring T
R
Response time
T
A
Alarm period t2 End of monitoring