10
where: DV = visualised value
MV= measured value
Example 1: It’s required that the instrument visualises the value effectively measured at 20° but, at 200°, it has to visualise 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’s required that the instrument visualises 10° whilst the value effectively measured is 0°, but, at 500° it has to
visualise a value higher of 50° (550°).
Therefore : M1=0 ; D1=10 ; M2=500 ; D2=550
“rot” = (550 - 10) / (500 - 0) = 1,08
“OFSt” = 550 - (1,08 x 500) = 10
Using par.
“FiL”
it’s possible to
program a constant of time working as software filter referred to the input value measured, in
order to reduce the sensibility at the noises (increasing the time of the reading).
In case of measuring error the instrument supplies the power as programmed on par.
“OPE”.
This power will be calculated depending on the cycle time programmed for the PID controller, while for the ON/OFF
controllers the cycle
time is automatically considered equal to 20 sec.
(ex. In case 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 measuring error will exist.)
Using par.
“InE”
it’s also possible to decide which are the conditions of the input error allowing the instrument to give as
output the power programmed on par. “OPE”.
The possibilities of par. “InE” are :
= Or : the condition occurs in case of overrange or probe breakage
= Ur : the condition occurs in case of underrange or probe breakage
= Our : the condition occurs in case of overrange or underrange or probe breakage
Using par.
“diSP”,
located in the group
“
]
PAn”,
it’s possible to define the normal visualization of the display which can be the
process variable (dEF), the control power (Pou), the active Set Point (SP.F) the Set Point operating when there are active
ramps (SP.o) or alarm threshold AL1, 2 or 3 (AL1, AL2 or AL3).
Still in the group
“
]
PAn”
it’s present par.
“AdE”
that defines the 3 led shift index functioning.
The switch on of the green led = indicates that the process value is comprised within the range [SP+AdE ... SP-AdE], the
switch on of the led – indicates that the process value is lower than [SP-AdE] and the switch on of the led + indicates that the
process value is higher than [SP+AdE].
4.2 – OUTPUT CONFIGURATION
The outputs of the instrument can be programmed entering the parameter group
“
]
Out”
where are present, depending on
the number of outputs available on the instrument, the relative parameters
“O1F” , “O2F” ,“O3F” ,“O4F”.
The outputs can be set for the following functioning :
- Main control output (1.rEG)
- Secondary control output (2.rEG)
- Alarm output normally open (ALno)
- Alarm output normally closed (ALnc)
- Output deactivated (OFF)
The coupling outputs number – alarms number can be effectuated in the group relative to the alarm (“
]
AL1”,”
]
AL2” o “
]
AL3”)
4.3 – ON/OFF CONTROLLER (1rEG)
All the parameters referred to the ON/OFF control are contained into the group
“
]
rEG”.
This type of control is obtainable programming par.
"Cont"
= On.FS or = On.FA and it 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 controller works in the following way : in 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 asymmetrical hysteresis and it
activates it again when the process value goes below value [SP - HSEt].
