the instrument will be swapped to normal control conditions
according to the previously programmed parameters.
To make the error “ErAt” disappear, press key P.
The autotuning cycle is limited to a maximum of 12 hours.
If the process has not ended in 12 hours the instrument will show
"noAt"
.
Instead, if a probe error should occur, the instrument will interrupt
the cycle being carried out.
The values calculated by Autotuning will be memorized
automatically by the instrument at the end of the correct completion
of the autotuning cycle in the parameters related to PID regulation.
Note :
The instrument is already programmed in our factory to
carry out auto-tuning at every instrument switch on ("Auto" = 1).
To activate the SELF-TUNING function proceed as follows
1) Program and activate the desired Set Point.
2) Program par. "Cont" =Pid.
3) Program par. "Func" according to the process to be controlled
through output 1.rEG.
4) Program an output as 2.rEG if the instrument controls a
dual-action plant
5) Program par.
"SELF"
= yES
6) Exit from the parameter programming.
7) Connect the instrument to the controlled plant.
8) Activate Self-tuning selecting par.
“tunE”
in the main menu (or
by correctly programming key “U”).
When the Self-tuning function is active, the led TUN is permanently
lit up and all the PID parameters ("Pb", "Int", "dEr", etc.) are no
longer visualized.
To stop the Auto-tuning cycle or deactivate the Self-tuning function
select one of the control types : "rEG", "OPLO" or "OFF" from the
menu “SEL”. If the instrument is switched off during Auto-tuning or
with the Self-tuning function activated, these functions will remain
activated the next time it is switched on.
4.9 - CONTROL POWER LIMITATION
Using this function, it is possible to limit the output control power
(separately for both control outputs) within a minimum limit and a
maximum limit .
It is only possible to use these limits if the PID control is single or
dual action and it may be useful to overcome some mechanical
problems of the actuators such as valves that do not open until the
output has reached at least 20% and/or are already completely
closed when the power has reached 80%.
The PID control of the instrument normally works producing power
between 0 and 100 % in the case of single-action PID and –100
(C) and 100 (H) % in the case of dual-action PID.
The function is therefore deactivated by setting “ro1.L” =0 “ro2.L” =
0 and “ro1.H” =100, “ro2.H” = 100.
By setting different values the power is lowered to within the limits
set in order to use the actuator’s dynamics to the maximum.
The parameters that can be set for this function, contained in the
“
]
rEG”
block are:
“ro1.L”
- minimum power in output from 1.rEG (H)
“ro1.H”
- maximum power in output from 1.rEG (H)
“ro2.L”
- minimum power in output from 2.rEG (C)
“ro2.H”
- maximum power in output from 2.rEG (C)
The limitation is not active under the “OPLO” manual control mode.
4.10 - LIMITATION OF THE CONTROL POWER VARIATION
SPEED
This function makes it possible to limit the variation speed of the
control power in output (separately for both control outputs).
It is only possible to use this function if the PID control is single or
dual action and can be useful for overcoming some problems with
the actuators that may need a slow progressive variation in power.
The parameters that can be set for this function, contained in the
block
“
]
rEG”,
are:
“OPS1”
- variation speed of the output power from 1.rEG (H)
expressed in [% / sec].
“OPS2”
- variation speed of the output power from 2.rEG (C)
expressed in [% / sec].
The limitation function is deactivated by setting the parameters =
InF and if “OPLO” is not active in manual control mode.
4.11 - SPLIT RANGE FUNCTION
The use of this function is only possible if the PID control is dual
function and can be used to delay or bring forward the intervention
of the actuators commanded by the instrument.
Using this function it is therefore possible to optimise the
intervention of the two actuators in such a way that their actions do
not overlap or so that they overlap so that they obtain the mix of the
two actions of the actuators.
Basically, this means setting two power offsets (one for direct
action and one for reverse action) that set the beginning of the
intervention of the actuator commanded by the output.
The parameters that can be set for this function contained in the
block
“
]
rEG”,
are:
“thr1”
: Power threshold at which output 1.rEG begins to operate.
“thr2”
: Power threshold at which output 2.rEG begins to operate.
Basically, if one wishes to bring forward the reverse action (1.rEG)
and delay the direct action (2.rEG) it is necessary to set positive
values on parameter “thr1” and negative values on parameter
“thr2”.
In this way, the area within which the two outputs are not activated
at the same time is increased.
Pb
Pb
time
-100%
thr2
thr1
100%
1rEG
(Cooling)
2rEG
(Heating)
0%
SP
PV
Vice versa if one wishes to extend the reverse action (1.rEG) and
bring forward the direct action (2.rEG) it is necessary to set nega-
tive values on parameter “thr1” and positive values on parameter
“thr2”.
In this way, the area within which the two outputs are activated at
the same time is increased.
Pb
Pb
time
thr1
thr2
100%
-100%
2rEG
(Cooling)
1rEG
(Heating)
0%
SP
PV
The split range function is deactivated by setting the respective
parameters =0.
time
Pb
Pb
100%
-100%
(Heating)
(Cooling)
2rEG
1rEG
0%
SP
PV
Note
: In order to simplify the explanation of the example graphs a
dual action control that is only proportional (and therefore with “dEr”
and “Int” = OFF) with “Prat” = 1.0 and “rS” = 0.0 was considered.
TECNOLOGIC spa - TLK 94
-OPERATING INSTRUCTIONS - Vr.01 - 01/10 - ISTR-MTLK94ENG1 - PAG. 8
