Basic Function Principles
The analog input terminals
 KL3444 and KL3448 process signals in the range between 0 and 20 mA
 KL3454 and KL3458 process signals in the range between 4 and 20 mA
with a resolution of 12 bits (4095 steps). They can supply the sensors from voltage fed in via the power contacts. The power contacts can optionally be supplied via the standard supply or via a power feed terminal with electrical isolation.
Process data output format
In the delivery state the process data are shown in two's complement form (integer 1 corresponds to 0xFFFF). Other presentation types can be selected via the feature register R32 (e.g. signed amount representation, Siemens output format).
Measured value  Input data  

KL3444, KL3448  KL3454, KL3458  decimal  hexadecimal 
0 mA  4 mA  0  0x0000 
10 mA  12 mA  16383  0x3FFF 
20 mA  20 mA  32767  0x7FFF 
Process data equations
The process data that are transferred to the Bus Coupler are calculated using the following equations:
Neither user nor manufacturer scaling is active
Y_{a} = (B_{a} + X_{ADC}) x A_{a}  (1.0) 
Y_{out} = Y_{a} 

Manufacturer scaling active (default setting)
Y_{1} = B_{h} + A_{h} x Y_{a}  (1.1) 
Y_{out} = Y_{1} 

User scaling active
Y_{2} = B_{w} + A_{w} x Y_{a}  (1.2) 
Y_{out} = Y_{2} 

Manufacturer and user scaling active
Y_{1} = B_{h} + A_{h} x Y_{a}  (1.3) 
Y_{2} = B_{w} + A_{w} x Y_{1}  (1.4) 
Y_{out} = Y_{2} 

Key
X_{ADC}:  Output values of the A/D converter 

Y_{out}:  Process data to PLC 

B_{a}, A_{a}:  Manufacturer gain and offset compensation  
B_{h}, A_{h}:  Manufacturer scaling  
B_{w}, A_{w}:  User scaling 
The equations of the straight line are enabled via register R32.