BECKHOFF DK9222-0112-0059 User Manual
Page 4
I/O
Measuring analog signals
Application Note DK9222-0112-0059
Live Zero (1/2…10 V | 4…20 mA)
Since a finite value (value > 0) of the lower measuring range (1/2 V, 4 mA) enables the permanent supply of power to the
sensor or the internal circuit without an external supply, internal monitoring (sensor defect/wire breakage) can also be realized
in this way. Signals with the classification “Live Zero” are typical for 2-wire sensors with high availability checking. The
Live Zero circuit is also advantageous for fault-finding: The signal curve can be measured with a multimeter over the entire
transmission link.
Note:
The Beckhoff products described below are not to be assigned to the HART classification. They are neither “HART-compatible”
nor are they suitable for use as intrinsically safe equipment in explosive zones.
The Beckhoff analog Bus Terminals | Evaluation units for analog signals
For the evaluation of analog sensor signals, Beckhoff offers an extensive range of Bus Terminals from the KL3xxx series, which
cover a broad range of applications in analog signal processing. The input circuit of the Bus Terminals differs between single-
ended and differential inputs. A single-ended input expects a signal with a fixed reference to ground.
Bus Terminals for the evaluation of current-based analog signals (KL3xxx | KS3xxx)
8-channel
True Zero
Live Zero
KL3448
| KS3448
8 x 1-wire-
connection, 12 bit
KL3458
| KS3458
8 x 1-wire-
connection, 12 bit
1-channel
KL3011
| KS3011
Differential input,
12 bit
KL3041
| KS3041
loop-powered,
12 bit
KL3021
| KS3021
Differential input,
12 bit
KL3051
| KS3051
loop-powered,
12 bit
4-channel
KL3444
| KS3444
4 x 2-wire-
connection, 12 bit
KL3044
| KS3044
12 bit
KL3454
| KS3454
4 x 2-wire-
connection, 12 bit
KL3054
| KS3054
12 bit
2-channel
KL3012
| KS3012
Differential input,
12 bit
KL3042
| KS3042
loop-powered,
12 bit
KL3112
| KS3112
Differential input,
16 bit
KL3142
| KS3142
16 bit, 0,05%
KL3022
| KS3022
Differential input,
12 bit
KL3052
| KS3052
loop-powered,
12 bit
KL3122
| KS3122
Differential input,
16 bit
0 ... 20 mA
4 ... 20 mA
+
0
+
0
Tab. 2 Bus Terminals for the evaluation of current-based analog signals
New Automation Technology
Beckhoff
4
For application notes see disclaimer on the last page