ABB JDF200, Operating Instruction

Page: 21 / 36

2600T Series | OI/JDF200-EN Rev. E 21
7 Operation
8.4 7.4 Output functions
JDF200 provides a selection of output functions, as follows:
— Linear (default setting)
— Sq. Root (x)
— Sq. Root (x
3
)
— Sq. Root (x
5
)
— Custom linearization table.
— Cylindrical lying tank.
— Spherical tank.
These output functions can be activated through the LCD
menu.
Important.
Before selecting a transfer function different than
“linear”, the input value (4...20 mA) should be verified to be linear
with the process primary variable otherwise the indication on the
display will be affected by a double operation.
8.4.1 7.4.1 Linear
Using this function, the relation between the indicator scale /
output value and the input value is linear (i.e. 4 mA input
corresponds 0% indicator scale, at 20 mA input corresponds
100% indicator scale).
Figure 9: Linear Output
8.4.2 7.4.2 Square root
Using this function, the relation between the indicator scele /
output value and the input value is square root.
To avoid the extremely high gain errors with the input value
approaching 4 mA, the indicator scale / output value is equal to
Zero Point up to a programmable CUTOFF value. Cutoff value
can be customized between 0% and 20%, referred to the
indicator scale / output range; default value is 6%.
The indicator scale / output value can then be linear with proper
slope and intercept zero up to a programmable LIN POINT value.
The linearization point value could either be 0% or in between
5% and 20% referred to the indicator scale / output range;
default value is 5%. Square root transfer funtion is finally applied.
8.4.3 7.4.3 Square root to the 3
rd
power
Using this function, the relation between the indicator scale /
output value and the input value is square root to the 3
rd
power.
8.4.4 7.4.4 Square root to the 5
th
power
Using this function, the relation between the indicator scale /
output value and the input value is square root to the 5
th
power.
8.4.5 7.4.5 Custom linearization curve
Using this function, the relation between the indicator scale /
output value and the input value is identified by a table with a
maximum of 22 points (input, output), in between 0% and 100%.
The first point is alway 0% and the last is 100%. The predefined
table can be uploaded at factory as option on request.
8.4.6 7.4.6 Cyclindrical lying tank
Using this function, the relation between the indicator scale /
output value and the input value is identified by a polynomial
proxy describing the cylindrical lying tank shape.
8.4.7 7.4.7 Spherical tank
Using this function, the relation between the indicator scale /
output value and the input value is identified by a polynomial
proxy describing the spherical tank shape.
8.5 7.5 Software release history
Revision
Description
Release
date From To
1.0.6 First release 04/2016
1.0.6 1.1.0
Bug Fixing:
— Corrected bug that caused the ‘%’ unit not to
be applied to any linearization type different
from “Linear”
— Corrected bug of Spanish HMI menus.
Improvements
— Differentiation between Transmitter alarms and
Process alarms.
— Static dataclasses objects reviewed.
05/2016
LINEAR
POINT
CUTOFF
Y= 0
Y= mX
Y
X
Y= √ X
Figure 10: Square root transfer function