S5-115F Manual
Rules Governing the Use of the S5-115F
10.5
Monitoring Times for Synchronization FB Calls (FB 254 SYNC)
The subunits must be synchronized for the following purposes:
•
Updating of user times
•
Servicing of process interrupts (OB 2)
•
Servicing of time interrupts (OB 13)
•
SINEC L1 processing
•
Programmer operation
The program for the operating system is organized so that it synchronizes the two subunits
automatically at intervals of
•
20 ms, if no SINEC L1 LAN is installed
•
40 ms, if a single or double, redundant, SINEC L1 LAN is installed.
In the user program you must make your own arrangements for synchronizing the two subunits.
You do this by calling FB 254 SYNC in the user program.
The S5-115F monitors the interval between the synchronization calls because they are of crucial
importance for the accuracy of user timers, the accuracy of the response to interrupts and for the
transmission times of the SINEC L1 LAN.
Synchronization of times in the user program
The accuracy of times in the user program depends on the intervals between synchronization calls.
The absolute error is:
•
maximum
20 ms+synchronization call interval
•
mean
5 ms+half the synchronization call interval
If the interval for updating user timers configured by COM 115F is exceeded as a result of too few
synchronization calls in the user program, the S5-115F will enter the STOP mode.
Synchronization for time and process interrupts
The response time for time and process interrupts also depends on the intervals between
synchronization calls. The response time to a process interrupt (OB 2) is:
•
maximum 10 ms+synchronization call intervall
•
minimum 30 ms
The interval between time interrups is programmable from 100 msec. upward. The deviation from
the programmed interval is:
•
maximum
20 ms+synchronization call interval
•
mean
5 ms+half the synchronization call interval
Synchronization call intervals for interrupt processing are monitored by the S5-115F operating
system with a configurable time interval. If the monitoring time is exceeded, the S5-115F stops.
Synchronization for SINEC L1 LAN
Data traffic via the SINEC L1 LAN is also monitored with a configurable safety time. Data traffic
with all configurable communications partners (except the master PC) must be completed within
this safety time, otherwise the Receive mailbox is deleted for safety reasons. If you use the SINEC
L1 LAN, we recommend that you call FB 254 every 30 to 40 ms, if possible.
EWA 4NEB 811 6148-02
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