KL4434 and KL4438 - Basic function principles

The KL4404 and KL4408 analog output terminals generate signals in the range 10 V to +10 V with a resolution of 12 bits (4095 steps). The outputs are single ended and have a common ground potential.

Format of the output values

In the delivery state the process data are shown in two's complement form ( -1integercorresponds to 0xFFFF). The feature register can be used to select other display options (e.g. signed amount representation, Siemens format).

Output value

Output voltage

hexadecimal

decimal

0x8000

-32768

-10 V

0xC001

-16383

-5 V

0x0000

0

0 V

0x3FFF

16383

+5 V

0x7FFF

32767

+10 V

Process data equations

The process data, which are transferred to the Bus Terminal, are calculated based on the following equations:

Neither user nor manufacturer scaling is active

Ydac = X x Aa + Ba

(1.0)

Manufacturer scaling active (default setting)

Y1 = Bh + Ah x X

(1.1)

Ydac = Y1 x Aa + Ba

 

User scaling active

Y2 = Bw + Aw x X

(1.2)

Ydac = Y2 x Aa + Ba

 

Manufacturer and user scaling active

Y1 = Bh + Ah x X

(1.3)

Y2 = Bw + Aw x Y1

(1.4)

Ydac = Y2 x Aa + Ba

 

Key

X:

Controller process data

 

Ydac:

Process data for D/A converter

 

Ba ,  Aa:

Manufacturer gain and offset compensation

(R17, R18)

Bh ,  Ah:

Manufacturer scaling

(R19, R20)

Bw,  Aw:

User scaling

(R33, R34)

 

The equations of the straight line are activated via register R32.