WAGO-I/O-SYSTEM 750
Process Image
73
753-668/000-004 4FAI 0/4-20 mA Diff PROFIsafe
Manual
Version 1.0.0, valid from HW/SW Version 01/01
5.9.2.3
Measurement Range 4
… 20 mA with Wire Break Detection Disabled
Table 44: Siemens S7 with Parameterizable Substitute Values, 4
… 20 mA, Wire Break Detection
Disabled
Measurement
Range
Unit
Channel
Status
Range
Decimal
Hexadecimal
> 25 mA
Parameterizable substitute
value
1
0
Overload
25
…
> 22.814 mA
Parameterizable substitute
value
1
0
Overflow
22.814
…
20.0006 mA
32511
…
27649
0x7EFF…
0x6C01
1
Overrange
20
…
4.0005787 mA
27648
… 1
0x6C00
… 0x1
1
Nominal range
4.00 mA
0
0x0
3.9995
…
0.4444 mA
−1 …
−6144
0xFFFF
…
0xE800
1
Underrange
< 0.4444
…
0 mA
Parameterizable substitute
value
1
0
Underflow
1
In “S7 F/FH Systems” an extra substitute value is output for this value in case of overload,
overflow or underflow in the safety program.
In “S7 Distributed Safety”, the substitute value 0 is provided for the safety program instead of the
parameterizable substitute value.
5.9.3
RIOforPA Representation
Additional measures required for “RIOforPA” in measurement range
0
… 20 mA.
In measurement range 0
… 20 mA, the F I/O module does not monitor the
underflow of defined input currents in the analog value representation
“RIOforPA”. As a result, a wire break cannot be detected by the F I/O module.
Plan appropriate measures to detect errors.