44
Device Description
WAGO-I/O-SYSTEM 750
753-668/000-004 4FAI 0/4-20 mA Diff PROFIsafe
Manual
Version 1.0.0, valid from HW/SW Version 01/01
3.6.10.3.1.1 Secure Detection of a Discrepancy Timeout
The following formula can be used to calculate the minimum actual discrepancy
time between two input signals
T
D,min
as a result of which the F AI module will
certainly report a discrepancy error.
𝑻
D,min
= Discrepancy Time × 𝟏. 𝟎𝟏𝟐𝟑𝟑 + 𝑻
GAD
Factor
Value
T
D,min
Minimum actual discrepancy time between two input
signals
Discrepancy Time
Configured discrepancy time
Discrepancy Factor
1.01233
T
GAD
Offset defined by smoothing and sampling
– see table
below for exact values
Table 24:
T
GD
: Offset Defined by Smoothing and Sampling
T
GAD
Sampling Frequency in Hz
100
60
50
10
S
moothi
ng
i
n
nu
mber
o
f
sa
mpl
ing
va
lue
s
1
25 ms
38 ms
45 ms
200 ms
2
34 ms
53 ms
63 ms
286 ms
4
53 ms
80 ms
98 ms
457 ms
8
87 ms
136 ms
166 ms
800 ms
16
156 ms
246 ms
303 ms
1487 ms
32
293 ms
464 ms
578 ms
2859 ms
64
567 ms
904 ms
1127 ms
5604 ms