Beckhoff KL3444, Документация

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Basic Function Principles
KL3444, KL3448, KL3454 und KL3458 19 Version: 3.2.0
4 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
( R17 [
}
51] , R18 [
}
51] )
B
h
, A
h
: Manufacturer scaling
( R19 [
}
51] , R20 [
}
51] )
B
w
, A
w
: User scaling
( R33 [
}
53] , R34 [
}
53] )