Definition Of The Long Discrepancy Time - Siemens SIMATIC S5-115F User Manual

Technical Description
• Long discrepancy time
Long discrepancy times are defined if discrepancies at the inputs
- last longer than 2550 msec. in error-free operation as a result of the particular process
- are greater than the defined short discrepancy time
- are to be differently defined bitwise.
Configure the long discrepancy time individually for each digital input. The 115F operating system
checks the DI bits for discrepancy only once per PLC cycle.
Digital input in
subunit A
Digital input in
subunit B
PII
2-8
Operating system detects discrepancy
Discrepancy time
PLC cycle n PLC cycle n+1
Figure 2-6. Definition of the Long Discrepancy Time
Discrepancy persists
Discrepancy no longer exists
PLC cycle n+2
S5-115F Manual
EWA 4NEB 811 6148-02