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displaying output magnitude, the output magnitude can be modified by pressing
or
. By setting M-A parameter,
the instrument can be locked at automatic or manual control mode to avoid entering manual operation by mistake.
Auto Tuning (AT)
When artificial intelligence PID control or standard PID control is chosen (CtrL=APId or nPId), the PID parameters can
be obtained by running auto-tuning. In basic display status, press
for 2 seconds, the “At” parameter will appear.
Press
to change
the value of “At” from “oFF” to “on”, then press
to active the auto-tuning process. During
auto tuning, “At” will flash at lower display window and the instrument executes on-off control. After 2 cycles of on-off
action, the instrument will obtain the values of PID control parameters. If you want to escape from auto tuning status,
press and hold
for about 2 seconds until the "At" parameter appears again. Change “At” from “on” to “oFF”, press
to confirm, then the auto tuning process will be cancelled. After satisfying PID parameters are obtained, At is
recommended to be “FoFF” which prevents activating auto tuning in basic display status.
Note 1:
The advanced artificial intelligence algorithm is able to avoid overshooting problem of standard PID algorithm
and achieve precise control.
Note 2:
If the setpoint is different, the parameters obtained from auto-
tuning are possibly different. So you’d better set
setpoint to an often-used value or middle value first, and then start auto-tuning. For the ovens with good heat
preservation, the setpoint can be set to the highest applicable temperature. It is forbidden to change SV during auto
tuning. Depending on the system, the auto-tuning time can be from several seconds to several hours.
Note 3:
Parameter CHYS (on-off differential, control hysteresis) has influence on the accuracy of auto-tuning.
Generally, the smaller the value of CHYS, the higher is the precision of auto tuning. But the value of CHYS parameter
should be large enough to prevent the instrument from error action around setpoint due to the oscillation of input. CHYS
is recommended to be 2.0.
Note 4:
AI series instrument has the function of self-adaptation. It is able to learn the process while working. The
control effect at the first run after auto tuning is probably not perfect, but excellent control result will be obtained after a
period of time because of self-adaptation.
3. PARAMETERS AND SETTINGS
3.1
Parameter Lock (Loc) and Field Parameters
In order to protect important parameters from being modified by mistake but also offer enough flexibility for field control,
parameter lock (Loc) and field parameters are introduced.
The parameters need to be displayed and modified in the work field are called Field Parameters. The set of field
parameters is a subset of the whole parameter set, and can be freely chosen by user.
Loc can authorize different security right as below:
Loc=0
～
1, allowed to modify field parameters and setpoint, and execute auto tuning;
Loc=2, a
llowed to modify field parameters, but can’t modify setpoint.
Loc=3
～
255: can only modify “Loc”
Setting Loc=PASd (Password, a number between 256 and 9999. Default is 808) and then pressing
to confirm will
enter the complete parameter table and modify all parameters.
1 to 8 field parameters can be defined by parameters EP1 to EP8. If the number of the field parameters is less than 8,
the first idle EP parameter should be set to “nonE”.
Parameters
EP1
EP2
EP3
EP4
EP5
EP6
EP7
EP8
Loc
Default Value
HIAL
LoAL
HdAL
LdAL
nonE
nonE
nonE
nonE
0
You can redefine field parameters and Loc to change operation style. For example, you can execute auto tuning from field
parameter instead of by pressing
in basic display status, and only take HIAL and HdAL as field parameter.
Parameters
EP1
EP2
EP3
EP4
EP5
EP6
EP7
EP8
Loc
At
Default Value
HIAL
HdAL
At
nonE
nonE
nonE
nonE
nonE
0
FoFF
