BECKHOFF KL4112 - Manual (Page 6)

Description of functions
6 KL4112
Description of functions
The analog output terminal KL4112 generates output signals within the
range from 0 – 20 mA. The output current is output by the terminal with up
to 16-bit resolution. The output current is electrically isolated from the ter-
minal bus level.
Input format of
process data In the default setting, process data is entered in twos complement (integer
-1 corresponds to 0xFFFF).
Process data item (Hex/decimal) Output value
0x0000 (0) 0 mA
0x3FFF (16383) 10 mA
0x7FFF (32767) 20 mA
LED Display
The two RUN LEDs indicate the operating state of the affiliated terminal
channel.
RUN LED:
On – normal operation
Off – watchdog-timer overflow has occurred. The green LEDs go off if no
process data is transferred by the bus coupler for 100 ms. The output out-
puts a current that is configurable by the user (see feature register).
Process data The process data arriving from the bus coupler is output to the process as
follows.
X = Process data of the PLC
B_a,A_a = Manufacturer scaling (R17,R28)
B_h,A_h = Manufacturer scaling (R19,R20)
B_w,A_w = User scaling (R33,R34)
Y_dac = Output value to the DA converter
Neither user nor manufacturer scaling active:
Y_0 = B_a + A_a*X
(1.0)
Y_dac = X
Manufacturer scaling active:
Y_1 = B_h + A_h * Y_0 (1.1)
Y_dac=Y_1
User scaling active:
Y_2 = B_w + A_w * Y_0
(1.2)
Y_dac=Y_2
Manufacturer and user scaling active:
Y_1 = B_h + A_h * Y_0
(1.3)
Y_dac = B_w + A_w * Y_1 (1.4)
The straight-line equations are activated via R32.