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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 func-
tions :
• 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”).

ON/OFF CONTROL (1REG)
All the parameters referring to the ON/OFF
control are contained in the group “]rEG”.
This type of control can be obtained by pro-
gramming par."Cont" = On.FS or = On.FA  and
works on the output programmed as 1.rEG,
depending on the measure, on the active Set
Point “SP”, 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 [SP + HSEt] in case of
symmetrical hysteresis, or [SP] in case of asym-
metrical hysteresis and is then activated again
when the process value goes below value [SP -
HSEt]. 
Vice versa, in case of direct action or cooling
("Func”=CooL), it deactivates the output, when
the process value reaches [SP - HSEt] in case of
symmetrical hysteresis, or [SP] in case of asym-
metrical hysteresis  and is activated again when
the process value goes above value [SP + HSEt].

NEUTRAL ZONE ON/OFF CONTROL (1REG -
2REG)
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 1rEG
and 2rEG and the par. “Cont” = nr .
The Neutral Zone control is used to control
plants in which there is an element which caus-
es 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 pro-
grammed outputs depending on the measure-
ment, on the active Set Point “SP” and on the
hysteresis "HSEt".
The control works in the following way : it deac-
tivates the outputs when the process value
reaches the Set Point and it activates the output
1rEG when the process value goes below value
[SP - HSEt], or it activates the output 2rEG when
the process value goes above [SP + HSEt]. 
Consequently, the element causing a positive
increase has to be connected to the output pro-
grammed as 1rEG while the element causing a
negative increase has to be connected to the
output programmed as 2rEG.

If 2rEG output is used to control compressor is
possible to use the “Compressor Protection”
function that has the meaning to avoid com-
pressor “short cycles”.
This function allows a control by time on the
output 2rEG 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 deactiva-
tion.
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 2rEG output blinks during
the phases of output activation delay, caused by
“Compressor Protection” function.

SINGLE ACTION PID CONTROL (1REG)
All the parameters referring to PID control are
contained in the group “]rEG”.
The Single Action PID control can be obtained
by programming par."Cont" = Pid  and works on
the output 1rEG depending on the active Set
Point “SP”, on the functioning mode "Func” and
on the instrument’s PID algorithm with two
degree of freedom.

In order to obtain good stability of the process
variable, in the event of fast processes, the cycle
time “tcr1” has to have a low value with a very
frequent intervention of the control output.
In this case use of a solid state relay (SSR) is
recommended for driving the actuator.

EWTQ 905

3/8

OUT

SP1

PV

off

ON

HEAt - On.FA

OUT

time

HSEt

SP1

PV

HSEt

time

CooL - On.FA

ON

ON

ON

ON

ON

off

off

off

CooL - On.FS

HEAt - On.FS

ON

ON

OUT

SP1

off

PV

off

ON

HSEt

time

OUT

ON

SP1

PV

ON

off

off

ON

time

HSEt

HSEt

HSEt

1.rEG

1.rEG

1.rEG

1.rEG

0N

OUT 2.rEG

(cooling)

OUT 1.rEG

(heating)

SP1

PV

off

0N

off

off

off

0N

time

HSEt

HSEt

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,

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Содержание EWTQ 905

Страница 1: ...figuration para meters menu Once the desired item has been selected push key set to confirm Selecting OPEr and ConF gives the possibili ty of accessing other menus containing addi tional parameters an...

Страница 2: ...with normalised analogue input signals it is first nec essary to program the desired resolution on par dP 0 1 1 0 1 2 0 01 3 0 001 and then on par SSC the value that the instrument must visualise at t...

Страница 3: ...Point SP and on the hysteresis HSEt The control works in the following way it deac tivates the outputs when the process value reaches the Set Point and it activates the output 1rEG when the process va...

Страница 4: ...matically calculate the fol lowing parameters Pb Proportional Band tcr1 Cycle time of the output 1rEG Int Integral Time dEr Derivative Time FuOC Fuzzy Overshoot Control and for the Double Action PID c...

Страница 5: ...of SP EWTQ 905 5 8 LoAb off ON AL1 AL1 PV HiAb HAL1 time off ON AL1 PV time HAL1 off off ON OUT off off ON OUT AL1 SP1 Unit PV SP1 Value change SP1 time min SLor SLor LoAb ABSOLUTE LOW ALARM The alarm...

Страница 6: ...for temperature probes tc J K RTD Pt 100 IEC PTC KTY 81 121 990 W 25 C NTC 103AT 2 10KW 25 C or mV sig nals 0 50 mV 0 60 mV 12 60 mV or normal ized signals 0 4 20 mA 0 1 V 0 1 5 V 0 2 10 V Normalized...

Страница 7: ...AL1H High threshold band alarm AL1 or Maximum set alarm AL1 for high or low alarm AL1L 9999 9999 20 HAL1 Alarm AL1 hysteresis OFF 9999 1 21 AL1d Activation delay of alarm AL1 OFF 9999 sec OFF 22 AL1i...

Страница 8: ...rms if the relative parameters ALni have been programmed yES 44 5 98 48 OUT2 48 ST AT OUT1 9 5 SET EWTQ 905 F set MAX 9 mm PANEL GASKET BRACKET TYPE 1 BRACKET TYPE 2 MECHANICAL DIMENSIONS PANEL CUT OU...

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