KPM PROCESS SENSORS METIS M311 Operating Manual page 59

METIS M311 / M322 / H311 / H322 (12-pin device connector)
- Hold time: when reaching the desired value, the setpoint value in can be maintained at the current value.
The control process stops automatically after the hold time is elapsed.
Click the expand icon to open the control parameters sorted into groups.
▪ PID parameters:
- Proportional band Xp: The proportional band represents the reciprocal of the gain of the controller (En-
tering 0.1-1000%, 0.1 = highest gain, 1000 = lowest gain).
- Integral time Ti: The integral time constant represents a kind of smoothing or delay.
INFO
Ti is a multiple of the sampling time. Therefore, changes in the sample have an impact on this
value.
- Derivative time Td: The derivative time constant slowdowns the rapid rise to prevent overshooting (if, for
example, the actual value has almost reached the target value but still strong increases, Td slows a fur-
ther increasing to prevent an overshoot).
INFO
Td is a multiple of the sampling time. Therefore, changes in the sample have an impact on this
value.
- Sampling time: Select how quick temperature values will be read out of the sensor. Select the parameter
depending on the inertia of the heating process
INFO
Ti and Td are a multiple of the sampling time. Therefore, changes in the sampling effect changes
in Ti and Td.
▪ Power adaptation:
- P-min: The minimum control output power defines the power set to the control output at least.
- P-max: The maximum control output limits the power to the entered value.
- P-zsc: Limits the control output power as long as the beginning of the pyrometer's temperature range is
reached. This is useful to avoid a too fast start of a heating process because the object temperature is out
of the pyrometer's temperature range.
- P-dynamic: Limits the power, the control output can control suddenly (standard 100%).
▪ Other functions:
- Setpoint limit 1 and 2: Activates every selected "setpoint limit" output (see
Outputs and under
low. The required temperature has to be set relative to the setpoint temperature (in the control parameter
field), not as absolute value.
- Setpoint deviation: defines the maximum permissible deviation between setpoint and actual value. Used
to detect if a ramp is within tolerance and then initiate the subsequent hold time.
▪
The AutoTune function enables to detect automatically useful values for the proportional Xp and
integral time constant Ti. The function tries to find the values Xp and Ti without overshooting the setpoint
temperature.
- The AutoTune target temperature defines the temperature that is used for Xp and Ti determination. The
entry occurs in % and defines the difference between setpoint and actual value (example: setpoint is
1000°C, the measurement object is cold which means the actual value is the pyrometer's beginning of
temperature range and thus, for example, 500°C, then the target temperature is 750°C at 50% factory
setting). Only a value below 100% prevents a temperature exceeding during P-I-determination and thus a
possibly material destruction due to overheating.
- Next start with AutoTune: Check this box to activate the AutoTune function with the next controller start.
Starting the controller with "Start" will start first the AutoTune process followed by the programmed control
process. This also works fort an external control start. The function is only active for one controller start
and will be unchecked with the next start.
- Controller start always with AutoTune: Starts every time the AutoTune function when the controller is
started.
INFO
The AutoTune process always starts from the current actual value (measured value).
At a restart any residual heat of the object can thus potentially lead to unusable values.
→
7.1.5 Configurable Inputs /
4.1.4
Outputs) if set temperature is exceeded or falls be-
Configurable Inputs /
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