Siemens SIMATIC S5 Manual page 24

S5-115F Manual
• Absolute AI deviation
This value has two functions:
The value configured here is interpreted during the AI test as the tolerable difference
between the analog test value displayed and the analog value read in.
The S5-115F monitors analog input deviations on both subunits.
The value defined here for "Min. absolute AI deviation" is always significant if you have
selected a relative tolerance range (e.g. 5 %) when configuring analog input modules.
Electromagnetic interference can quickly cause relative deviations to be exceeded,
especially in the case of small analog values. Whenever the relative tolerance range is
exceeded, the 115F operating system checks to establish whether or not the value for
"Absolute AI deviation" has been exceeded. The system only responds if this minimum
value has been exceeded.
• Global lower / upper wire-break limits
Enter here the limits of the range within which a value is to be interpreted as a wire break. Set
a default for wire break monitoring at this point. You will generally use the "global wire break
limits" when several analog inputs have the same standardized value range.
The limits for wire break monitoring are also scanned when configuring FB 250 ANEI. If you
want the default value for "global wire break monitoring", enter the value "-32768" for the
"ODGR" (upper wire break limit) and "UDGR" (lower wire break limit) parameters of
FB 250 ANEI.
If you do not want to use the "global wire break limits" when configuring FB 250 ANEI, you
must assign the local "ODGR" and "UDGR" parameters accordingly in FB 250 ANEI.
EWA 4NEB 811 6149-02
Configuring with COM 115F
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