Honeywell VRX180 Manuale Utente

This CV type can be used to characterize a valve (Figure 4-8) or an input signal (Figure 4-9).  You enter 
a custom curve of up to 19 segments (20 X,Y coordinates).  The input is compared with the X values 
and its corresponding Y value becomes the output CVn OV.  Interpolation between coordinates is 
straight line.  See Figure 4-7. 

If the input value is outside the range of X values, the nearest X value is used, the output will be 
clamped to the corresponding Y value and the displayed output value will flash. 

X1

X2

X3

X4

X5

X6

Y1, Y2

Y3, Y4

Y5

Y6

 

 

Table 4-33 describes the Function Generator prompts.  See Table 4-2 for additional prompts. 

 

RANGE LOW 

OFF or number 

Enter the output’s lower display limit.  Output is not clamped 
or flashed when it exceeds this limit.  Default value is Y1 
value. 

RANGE HIGH 

OFF or number 

Enter the output’s lower display limit.  Output is not clamped 
or flashed when it exceeds this limit.  Default value is Y1 
value. 

INPUT 

OFF, analog parameter, 
number 

This value will be compared with the X values of the curve.  
The corresponding Y value will be the CV output. 

X1, Y1, X2, Y2…X20, 

Y20 

OFF or number 

Use these prompts to plot a curve using 2 to 20 X,Y 
coordinates.  X values must increase as Xn increases. 

FEEDBACK 

OFF, analog parameter, 
number 

For valve characterization, select AO# BC to propagate the 
back calculation (BC) value from a downstream Analog 
Output.  Also, program the upstream loop’s feedback with 
this CV’s back calculation value (CV# BC).  See Figure 4-8. 

Attention: If feedback is programmed to an analog 
parameter or a number, the X and Y values must define a 
curve that is not bell shaped or complex.  That is, all Y values 
must be increasing or decreasing.