In this case, in order to decide which values to program on par.
“OFSt” and “rot”, the following formulae must be applied :
“rot” = (D2-D1) / (M2-M1)
“OFSt” = D2 - (“rot” x M2)
where:
M1 =measured value 1
D1 = visualisation value when the instrument measures M1
M2 =measured value 2
D2 = visualisation value when the instrument measures M2
It then follows that the instrument will visualise :
DV = MV x “rot” + “OFSt”
where: DV = visualised value
MV= measured value
Example 1: It is desired that the instrument visualises the value
effectively measured at 20° but that, at 200°, it visualises a value
lower than 10° (190°).
Therefore : M1=20 ; D1=20 ; M2=200 ; D2=190
“rot” = (190 - 20) / (200 - 20) = 0,944
“OFSt” = 190 - (0,944 x 200) = 1,2
Example 2: It is desired that the instrument visualises 10° whilst the
value actually measured is 0°, but, at 500° it visualises a 50° higher
value (550°).
Therefore : M1=0 ; D1=10 ; M2=500 ; D2=550
“rot” = (550 - 10) / (500 - 0) = 1,08
“OFSt” = 550 - (1,08 x 500) = 10
By using par.
“FiL”
it is possible to
program time constant of the
software filter for the input value measured, in order to reduce
noise sensitivity (increasing the time of reading).
In case of measurement error, the instrument supplies the power
as programmed on par.
“OPE”.
This power will be calculated according to cycle time programmed
for the PID controller, while for the ON/OFF controllers the cycle
time is automatically considered to be equal to 20 sec. (e.g. In the
event of probe error with ON/OFF control and “OPE”=50, the
control output will be activated for 10 sec., then it will be
deactivated for 10 sec. and so on until the measurement error
remains.).
In the group
“
]
PAn”
the par.
“AdE”
is present that defines the 3
led shift index functioning.
The lighting up of the green led = indicates that the process value
is within the range [SP1+AdE ... SP1-AdE], the lighting up of the
led – indicates that the process value is lower than [SP1-AdE] and
the lighting up of the led + indicates that the process value is higher
than [SP1+AdE].
4.2 - OUTPUTS CONFIGURATION
The instrument’s outputs can be programmed by entering the group
of parameters
“
]
Out
, where the relative parameters
“O1F”
and
“O2F”
(depending on the number of outputs available on the
instrument) are located.
The outputs can be set for the following functions :
- Main control output (1.rEG)
- Secondary control output (2.rEG)
- Alarm output normally open (ALno)
- Alarm output normally closed (ALnc)
- Alarm output normally closed with led reverse indication (ALni)
- Output deactivated (OFF)
The coupling outputs number outputs – number alarms can be
made in the group referring to the alarm to the alarm (“
]
AL1”).
4.3 - ON/OFF CONTROL (1.rEG)
All the parameters referring to the ON/OFF control are contained in
the group
“
]
rEG”.
This type of control can be obtained by programming par.
"Cont"
=
On.FS or = On.FA and works on the output programmed as
1.rEG,
depending on the measure, on the Set Point
“SP1”
, on the
functioning mode
"Func”
and on the hysteresis
"HSEt
".
The instrument carries out an ON/OFF control with symmetric
hysteresis if “Cont" = On.FS or with asymmetrical hysteresis if
“Cont” = On.FA.
The control works in the following way : in the case of reverse
action, or heating (“FunC”=HEAt), it deactivates the output, when
the process value reaches [SP1 + HSEt] in case of symmetrical
hysteresis, or [SP1] in case of asymmetrical hysteresis and is then
activated again when the process value goes below value [SP1 -
HSEt].
Vice versa, in case of direct action or cooling ("Func”=CooL), it
deactivates the output, when the process value reaches [SP1 -
HSEt] in case of symmetrical hysteresis, or [SP1] in case of
asymmetrical hysteresis and is activated again when the process
value goes above value [SP1 + HSEt].
O U T
S P 1
P V
o ff
O N
H E A t - O n .F A
O U T
t im e
H S E t
S P 1
P V
H S E t
tim e
C o o L - O n .F A
O N
O N
O N
O N
O N
o ff
o ff
o ff
C o o L - O n .F S
H E A t - O n .F S
O N
O N
O U T
S P 1
o ff
P V
o ff
O N
H S E t
t im e
O U T
O N
S P 1
P V
O N
o ff
o ff
O N
tim e
H S E t
H S E t
H S E t
1 .rE G
1 .rE G
1 .rE G
1 .rE G
4.4 - NEUTRAL ZONE ON/OFF CONTROL (1.rEG - 2.rEG)
All the parameters referring to Neutral Zone ON/OFF control are
contained in the group
“
]
rEG”.
This type of control can be obtained when 2 outputs are
programmed respectively as 1.rEG and 2.rEG and the par.
“Cont”
= nr .
The Neutral Zone control is used to control plants in which there is
an element which causes a positive increase (ex. Heater,
humidifier, etc.) and an element which causes a negative increase
(ex. Cooler, de-humidifier, etc).
The control functions works on the programmed outputs depending
on the measurement, on the Set Point
“SP1”
and on the hysteresis
"HSEt
".
The control works in the following way : it deactivates the outputs
when the process value reaches the Set Point and it activates the
output 1.rEG when the process value goes below value [SP1 -
HSEt], or it activates the output 2.rEG when the process value goes
above [SP1 + HSEt].
Consequently, the element causing a positive increase has to be
connected to the output programmed as 1.rEG while the element
causing a negative increase has to be connected to the output
programmed as 2.rEG.
0N
O U T 2.rEG
(cooling)
O U T 1.rE G
(heating)
SP 1
PV
off
0N
off
off
off
0N
tim e
H SEt
H SEt
If 2.rEG output is used to control compressor is possible to use the
“Compressor Protection” function that has the meaning to avoid
compressor “short cycles”.
This function allows a control by time on the output 2.rEG
activation, independently by the temperature control request.
The protection is a “delayed after deactivation” type.
This protection permits to avoid the output activation for a time
programmable on par. “
CPdt
” (expressed in sec.); the output
activation will occurs only after the elapsing of time “CPdt”.
The time programmed on parameter “CPdt” is counted starting from
the last output deactivation.
Obviously, whether during the time delay caused by the
compressor protection function, the regulator request should stop,
the output activation foreseen after time “CPdt” would be erased.
The function is not active programming “CPdt” =OFF.
The led relative to 2.rEG output blinks during the phases of output
activation delay, caused by “Compressor Protection” function.
TECNOLOGIC spa - TLK 48 B
- OPERATING INSTRUCTIONS - Vr. 03 - 12/04 - ISTR 06877 - PAG. 4
