Input 4; Input 0 - Festo CPX-4AE-4AA-H Operating Instructions Manual

Commissioning
Digital input value = (actual value - 4) x 27648 / 16
Actual value
> 22.81 mA
22.81 mA
Ü 20 mA
4 ... 20 mA
< 4 mA
1.19 mA
Tab. 35: Range of values for fixed data format (input 4 ... 20 mA)
7.5.3 Input 4 ... 20 mA - scalable data format
– Measuring range 4 ... 20 mA
– Scalable data format -32768 ... 0 ... 32767
– Scaling above the lower and upper critical limit
– Use of the critical limits for diagnostics
– Conversion of the current values 1.19 ... 22.81 mA (for sufficiently scaled data range)
– Overflow or underflow for values outside of the data range for actual values (> 22.81 mA or
< 1.19 mA) or digital input value (> 32767 or < -32768)
– Conversion of analogue actual value to the digital input value:
Digital input value = (actual value - 4) x (upper critical limit - lower critical limit) / 16 + lower critical
limit
To perform complete diagnostics: do not scale the measuring range above the complete data range.
Actual value
4 ... 20 mA
< 1.19 mA
Tab. 36: Range of values for scalable data format (input 4 ... 20 mA)
7.5.4 Input 0 ... 20 mA - fixed data format
– Measuring range 0 ... 20 mA
– Data format not scalable
– No underflow: actual values < 0 mA not possible (reverse polarity protection)
– Conversion of analogue actual value to the digital input value:
Digital input value = actual value x 27648 / 20
Actual value
23.52 mA
> 20 mA
Festo — CPX-4AE-4AA-H — 2021-06b
Digital input value
32767
32511
27649 ... 32511
0 ... 27648
-1 ... -4864
-4864
Digital input value
-32768 ... 32767
-32768
Digital input value
32511
27649 ... 32511
Meaning
Overflow
End of the measuring range
Overdrive range
Nominal range
Underdrive range
End of the measuring range
Meaning
Nominal range, freely scalable
Underflow
Meaning
End of the measuring range
Overdrive range
41