DPM1 User Manual, 1st Edition
User Manual - DPM1 Series Panel Meters
14
Scaling
Scaling consists of assigning a display value to each input signal value.
In linear processes
it is achieved by programming two coordinates (InP1, dSP1) and (InP2,
dSP2), between which is established a linear relation where each input signal value corresponds
to a display value. The relationship can be direct or reversed. In order to obtain more accuracy,
points 1 and 2 should be located approximately at both extremes of the process.
display2
display1
input1
Input2
Direct scale
input2
input1
display1
display2
Reversed scale
In nonlinear processes it is possible to program up to 16 input to display points. Each two
points are connected by a straight line and the whole is a curve that represents the relationship
between the input value and the display value.
Input
Display
1
2
3 4 5
In order to obtain more accuracy it is recommended to program the highest possible number
of points and reduce the segment length.
Input values must always be programmed in an
increasing or decreasing order. Avoid assigning two different display values to two equal
input values.
Display values can be entered in any order and even be repeated for different
inputs.
Below the first point programmed, the relationship established between the two first points of
the scale is followed. Above the last point programmed, the relationship established between the
two last points of the scale is followed.
Programming of the scale
There are two methods for programming the scale, the
SCAL
method and the
tEACH
method.
SCAL method
The input and display values are programmed manually. This method can be used when the
value of the signal supplied by the transducer at each point of the process is known.
tEACH method
The input values are introduced directly from actual process values. The input signal device
must be connected to the meter and operational when each point is programmed. The display
values are programmed manually. This method can be used when it is possible to bring the
process to the conditions of each one of the points to be programmed.
