4.12 - REACHING OF THE SET POINT AT CONTROLLED
SPEED AND AUTOMATIC SWITCHING BETWEEN TWO SET
POINTS (RAMPS AND DWELL TIME)
All the parameters referring to the ramps functioning are contained
in the group
“
]
rEG”.
It is possible to reach the set point in a predetermined time (in any
case longer than the time the plant would naturally need). This
could be useful in those processes (heating or chemical
treatments, etc.) where the set point has to be reached gradually,
in a predetermined time.
Once the instrument has reached the first Set Point (SP1) it is pos-
sible to have automatic switching to the second Set Point (SP2) af-
ter a set time, thus obtaining a simple automatic process cycle.
These functions are available for all the programmable controls
(PID single and double action, ON/OFF and Neutral Zone
ON/OFF).
The function is determined by the following parameters :
"SLor"
- Gradient of first ramp expressed in unit/minute
"SLoF"
- Gradient of second ramp expressed in unit/minute.
"dur.t"
- Dwell time of Set Point “SP1” before automatic switching
to Set Point “SP2” (expressed in hrs. and min.).
The functions are deactivated when the relative parameters are =
InF.
If is desired only one ramp (ex. to reach “SP1”) it is enough to
program on the par. "SLor" the desired value.
The ramp "SLor" it will always active at power on and when the
Active Set Point value is changed.
S P 1
[U n it]
S V
S P 1 V a lu e
c h a n g e
S P 1
tim e [m in .]
S L o r
S L o r
If it is desired an automatic cycle from the power on instead it is
necessary to program the par. "nSP" = 2, to program the two Set
Point values "SP1" and "SP2" and naturally to program the par.
"SLor", "dur.t" and "SLoF" with the desired values.
In this case at the end of the cycle all the ramps won't be more
active.
[ U n i t ]
S P 1
S V
A U T O
c h a n g e
S e t
d u r . t
S P 2
t i m e [ m i n . ]
S L o r
S L o F
Examples with starts from values lower than SP and with
decreasing of SP.
Note:
In case of PID control, if Auto-tuning is desired whilst the
ramp function is active, this will not be carried out until the tuning
cycle has been completed. It is therefore recommended that
Auto-tuning be started avoiding activating the ramp function and,
once the tuning is finished, deactivate Auto-tuning (“Auto” = OFF),
program the desired ramp and, if it automatic tuning is desired,
enable the Self-tuning function.
4.13 - SOFT-START FUNCTION
All the parameters referring to the Soft -Start functioning are
contained in the group
“
]
rEG”.
The Soft-Start function only works through PID control and allows
the limitation of control power when the instrument is switched on,
for a programmable period of time.
This is useful when the actuator, driven by the instrument, may be
damaged excess power supplied when the application is not yet in
the normal rating. (ex. for certain heating elements).
The function depends on the following parameters :
“St.P”
- Soft-Start power
“SSt”
- Soft-Start time (expressed in hh.mm)
“HSEt”
- End Soft Start cycle threshold
If both parameters are programmed with values other than OFF,
when switched on the instrument gives an output power as
programmed on par. “St.P” for the time programmed on par. “SSt”
or when is reached the absolute value programmed at par. “HSEt”.
Practically, the instrument works in manual condition and switches
to automatic control at the elapsing of time “SSt” or when is
reached the absolute value programmed at par. “HSEt”.
To disable the Soft-Start function simply program par. “SSt” = OFF.
Whenever, a measurement errors occurs during the Soft-Start
execution, the function is interrupted and the instrument gives an
output power as programmed on par. “OPE”.
If the measurement is restored, the Soft-Start is still deactivated.
If it’s desired to activate the Autotuning with Soft-Start set par.
“Auto”=4 / -4
The Autotuning will start automatically at the end of programmed
Soft-Start cycle (see. par. 4.8).
4.14 - ALARMS OUTPUTS FUNCTIONS (AL1, AL2, AL3, AL4)
The alarms depend on the process value (AL1, AL2, AL3, AL4) and
before setting them to work, it is necessary to know which output
the alarm has to correspond to.
First of all it is necessary to configure in the groups of parameters
“
]
Out ”,
the parameters relative to the outputs required as alarm
(“O1F”, “O2F”, “O3F”, “O4F”, “O5F”, “O6F”) programming the
parameter relating to the desired output as follows :
= ALno
if the alarm output has to be ON when the alarm is active,
while it is OFF when the alarm is not active
= ALnc
if the alarm output has to be ON when the alarm is not
active, while it is OFF when the alarm is active
Note:
In all the examples that follow is made reference to the alarm
AL1. Naturally the operation of the other alarms results analogous.
Have now access at the group
“
]
AL1”,
and program on par.
“OAL1”
, to which output the alarm signal has to be sent.
The alarm functioning is instead defined by parameters :
"AL1t "
- ALARM TYPE
"Ab1"
- ALARM CONFIGURATION
“AL1”
- ALARM THRESHOLD
“AL1L”
- LOW ALARM THRESHOLD (for band alarm) OR
MINIMUM SET OF AL1 ALARM THRESHOLD (for low or high
alarm)
“AL1H”
- HIGH ALARM THRESHOLD (for band alarm) OR
MAXIMUM SET OF AL1 ALARM THRESHOLD (for low or high
alarm)
“HAL1” -
ALARM HYSTERESIS
“AL1d”
- ALARM ACTIVATION DELAY (in sec.)
"AL1i"
- ALARM BEHAVIOUR IN THE EVENT OF
MEASUREMENT ERROR
"AL1t" - ALARM TYPE :
the alarm output can behave in six
different ways.
LoAb
= ABSOLUTE LOW ALARM: The alarm is activated when
the process value goes below the alarm threshold set on parameter
"AL1” and will be deactivated when it goes above the value
[AL1+HAL1].
With this mode is possible to program the minimum and the
maximum set of “AL1” by “AL1L” and “AL1H” parameters.
HiAb
= ABSOLUTE HIGH ALARM: The alarm is activated when the
process value goes higher than the alarm threshold set on
parameter "AL1" and will be deactivated when it goes below the
value [AL1 - HAL1].
With this mode is possible to program the minimum and the
maximum set of “AL1” by “AL1L” and “AL1H” parameters.
LoAb
off
ON
AL1
AL1
PV
HiAb
HAL1
time
off
ON
AL1
PV
time
HAL1
off
off
ON
OUT
off
off
ON
OUT
AL1
TECNOLOGIC spa - TLK 94
-OPERATING INSTRUCTIONS - Vr.01 - 01/10 - ISTR-MTLK94ENG1 - PAG. 9
