Siemens S7-300 Installation And Operating Manual page 275

"Tolerance window %, relative" parameter
The tolerance window is calculated as a percentage of the
represents the MIN or MAX value (depending on the parameter assignment of the standard
value) in this instant.
You can calculate the relative tolerance window using the following formula:
Calculate the maximum deviation of the current using the following formula:
With
● I
● I
● I
● T = Tolerance, in %
● ΔI
You can assign a value of 0.2 to 20% for the "Tolerance window %, relative" parameter for
each channel pair.
Figure 9-42 Relative deviation in % of the nominal range for measuring range 0 to 20 mA or 4 to 20 mA
Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
= Process standard value (min./max.)
EW
= 0 mA for measuring range 0 ... 20 mA
MA
= 4 mA for measuring range 4 ... 20 mA
MA
= Maximum deviation of current (+/-)
rel
9.3 SM 336; F-AI 6 x 0/4 ... 20 mA HART
smoothed
process value that
Analog modules
275