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Ascon Tecnologic - KM2 Line - ENGINEERING MANUAL - PAG. 14
•
You desire an auto tune calculation independently
from the starting conditions (e.g. Set Point change
during tune execution, etc).
Note:
Fast auto-tune can start only when the measured
value (PV) is lower than (SP + 1/2SP).
Available:
When [57] cont = PID.
Range:
-4... 8 where:
-4
Oscillating auto-tune with automatic restart at
all Set Point change;
-3
Oscillating auto-tune with manual start;
-2
Oscillating auto-tune with automatic start at the
first Power ON only;
-1
Oscillating auto-tune with automatic restart at
every Power ON;
0
Not used;
1
Fast auto tuning with automatic restart at every
Power ON;
2
Fast auto-tune with automatic start at the first
Power ON only;
3
FAST auto-tune with manual start;
4
FAST auto-tune with automatic restart at all Set
Point change.
5
EvoTune with automatic restart at every Power
ON;
6
EvoTune with automatic start at the first Power
ON only;
7
EvoTune with manual start;
8
EvoTune with automatic restart at all Set Point
change.
Note:
All auto-tunes are inhibited during program execution.
[59] Aut.r - Manual start of the auto-tune
Available:
When [57] cont = PID.
Range: oFF
The instrument is not performing the auto-tune;
on
The instrument is performing the auto-tune.
[60] HSEt - Hysteresis of the ON/OFF control
Available:
When [57] cont is different from PID.
Range: 0... 9999
engineering units.
[61] cPdt - Time for compressor protection
Available:
When [56] cont = nr.
Range: OFF
Protection disabled;
1... 9999
seconds.
[62] Pb - Proportional band
Available:
When [57] cont = PID.
Range: 1... 9999
engineering units.
Note:
Auto-tune functions calculate this value.
[63] ti - Integral time
Available:
When [57] cont = PID.
Range: OFF
Integral action excluded;
1... 9999
seconds;
inF
Integral action excluded.
Note:
Auto-tune functions calculate this value.
[64] td - Derivative time
Available:
When [57] cont = PID .
Range: oFF
Derivative action excluded;
1... 9999
seconds.
Note:
Auto-tune functions calculate this value.
[65] Fuoc - Fuzzy overshoot control
This parameter reduces the overshoot usually present at
instrument start up or after a Set Point change and it will be
active only in this two cases.
Setting a value between 0.00 and 1.00 it is possible to slow
down the instrument action during Set Point approach.
Setting
Fuoc = 1
this function is disabled.
PV
SP
time
2
1
3
Available:
When [57] cont = PID.
Range: 0... 2.00
.
Note:
Fast auto-tune calculates the Fuoc parameter while
the oscillating one sets it equal to 0.5.
[66] tcH - Cycle time of the heating output
Available:
When at least one output is programmed in order
to be the heating output (H.rEG) and
[57] cont = PID.
Range: 2... 130.0
seconds.
[67] rcG - Power ratio between heating and
cooling action (relative cooling gain)
The instrument uses the same PID parameter set for heat
and for cool action but the efficiency of the two actions are
usually different.
This parameter allows to define the ratio between the efficiency
of the heating system and the efficiency of the cooling one.
An example will help us to explain you the philosophy.
Consider one loop of a plastic extruder. The working
temperature is equal to 250°C.
When you want to increase the temperature from 250
to 270°C (
D
T = 20°C) using 100% of the heating power
(resistor), you will need 60 seconds.
On the contrary, when you want to decrease the temperature
from 250 to 230°C (
D
T = 20°C) using 100% of the cooling
power (fan), you will need 20 seconds only.
In our example the ratio is equal to 60/20 = 3 ([67] rcG = 3)
and it say that the efficiency of the cooling system is 3 time
more efficient of the heating one.
Available:
When two control action are programmed
(H.rEG and c.rEG) and [57] cont = PID.
Range: 0.01... 99.99
.
Note:
Auto-tune functions calculate this value.
[68] tcc - Cycle time of the cooling output
Available:
When at least one output is programmed in order
to be the cooling output (c.rEG).
Range: 2... 130.0
seconds.
[69] rS - Manual reset (integral pre-load)
It allows to drastically reduce the undershoot due to a
hot restart. When your process is steady, the instrument
operates with a steady power output (e.g.: 30%).
If a short power down occurs, the process restarts with a
process variable close to the Set Point while the instrument
starts with an integral action equal to zero.
Setting a manual reset equal to the average power output (in our
example 30%) the instrument will start with a power output equal
to the value it will use at steady state (instead of zero) and the
undershoot will become very little (in theory equal to zero).
Available:
When [57] cont = PID.
Range: -100.0... +100.0%
.