Siemens FM 458-1 DP Manual page 60

2 Timer mode
The SLB module operates as master. The SIMOLINK blocks in the CFC chart must be
configured in an interrupt task Ix (x=1 . . . 8).
Timing: A timer of the ITSL/EXM 448-1 module initiates, corresponding to the equivalent
sampling time, an interrupt, and therefore execution of interrupt task Ix. The SIMOLINK
telegrams are sent after the last SIMOLINK block has been calculated.
Timer interrupt
Processing time of the
SIMOLINK blocks
3 Automatic mode
The SLB module operates as master. The SIMOLINK blocks in the CFC chart must be
configured in an interrupt task Ix (x=1 . . . 8).
Timing: Each SYNC telegram which is received, initiates an interrupt, and therefore execution of
the interrupt task Ix. The SIMOLINK bus cycle is automatically re-initiated each time a SYNC
telegram is received. SIMOLINK telegrams are sent and received in parallel with the signal
processing (internal calculations).
SIMOLINK cycle
Processing time of the
SIMOLINK blocks
4 External mode
The SLB module operates as master. The SIMOLINK blocks in the CFC chart must be
configured in an interrupt task Ix (x=1 . . . 8).
Timing: The bask clock cycle T0 from the system initiates that telegrams are sent, and therefore
the start of the SIMOLINK cycle. A subsequently received SYNC telegram initiates an interrupt
and therefore execution of interrupt task Ix. The signal processing (internal calculations) are
realized after the SIMOLINK telegram has been sent and received.
T0 interrupt
SIMOLINK cycle
5 External cyclic mode
The SLB module operates as master. The SIMOLINK blocks in the CFC chart must be
configured in a cyclic task T1=T0.
Timing: The basic clock cycle T0 initiates that telegrams are sent (starts the SIMOLINK cycle)
and the SIMOLINK blocks are processed in T1=T0. The signals are processed (internal
calculation) at the same time as sending and receiving SIMOLINK telegrams.
T0 interrupt
SIMOLINK cycle
Processing time of the
SIMOLINK blocks
Cyclic task T1 = T0
Function Blocks - FM 458-1 DP
Edition 12.2004
SIMOLINK cycle
Interrupt task Ix
SYNC telegram
NOP
Processing time of the
SIMOLINK blocks
Interrupt task
SYNC telegram
Processing time of the
SIMOLINK blocks
Interrupt task Ix
Basic clock cycle T0
T0 interrupt
Processing time of the
SIMOLINK blocks
Timer interrupt
Processing time of the
SIMOLINK blocks
SYNC telegram
SIMOLINK cycle
T0 interrupt
SIMOLINK cycle
T0 interrupt
SIMOLINK cycle
SIMOLINK drive coupling
SIMOLINK cycle
SIMOLINK cycle
Processing time of the
SIMOLINK blocks
SYNC telegram
Processing time of the
SIMOLINK blocks
SIMOLINK cycle
Processing time of the
SIMOLINK blocks
5-3