EVCO EC4173 - Manual (Page 4)

4
PRODUCTS LINE '96
"AUTO-TUNING" FUNCTION
The "Auto-tuning" function has been studied to permit the instrument to calculate (during the process) the optimal value of the parameters used
during the temperature regulation, in order to use them during the conclusive part of the regulation.
Before activating an "Auto-tuning" function it is possible to determine the kind of requested temperature regulation:
- P.I.D. (parameters PI and Pd > 0)
- P.I. (parameter PI > 0 and parameter Pd = 0)
- P.D. (parameter PI = 0 and parameter Pd > 0)
- P. (parameters PI and Pd = 0).
If the parameter P2 is programmed at 1, it is possible to activate an "Auto-tuning" function pushing the key for 4 seconds at least: the display
shows the temperature read by the probe alternated to the indication "tun"; the keyboard of the instrument is locked except the key .
The function is essentially based on two phases:
- an initial phase during which the instrument regulates the temperature using the data programmed before the function activation, until the reaching
of a threshold depending on the initial environment temperature where the probe has been put and also depending on the setpoint
- a final phase during which the instrument activates the output at its maximum power, it computes the characteristics of the connected load
(also according to the controlled system) and determines the optimal value of the parameter Pb (PI and Pd too, if > 0 at the moment of the
function activation).
If during the final phase the instrument has been able to compute some useful data for the regulation, the function automatically ends; in this case
the instrument continues the temperature regulation using the data computed during the final phase of the function and displaying the temperature
read by the probe.
Vice versa, if during the final phase the instrument has not been able to compute some useful data for the regulation, the display shows "---" flashing
and the output gets deactivated.
To leave this alarm condition, it is necessary to push the key for 4 seconds at least or try to switch the power-supply off and then, switch
it on: in this case the instrument restores the temperature regulation using the data programmed before the activation of an "Auto-tuning" function
(normally an "Auto-tuning" function does not have success because at the moment of its activation the environment temperature where the probe
has been put is close to the setpoint or because during the final phase some noises have happened).
NOTES - the data computed during an "Auto-tuning" function get memorised by the instrument to be restored at its following start
- an "Auto-tuning" function on run can be deactivated pushing the key
for 4 seconds at least; in this case the instrument
restores the temperature regulation using the data programmed before the function activation.