Configuring
Application Module FM 458-1 DP - User Manual 4-23
A5E01078222-02 Edition 03.2009
the length of the transmit- or receive telegram (inputs or outputs)
may not exceed 32 bytes per slave.
all transmit- and receive blocks and the SYNPRO function blocks
must be configured in the same sampling time (on FM 458-1 DP).
the SYNPRO function block is configured as the last function
block in the processing sequence.
output SOK of function block SYNPRO should be connected with
the enable inputs of all (belonging to the slave group) transmit-
and receive blocks.
The bus circulating time must be less than the Synccycle minus 2 x
the sampling time. When the system is operational, it should be
checked whether the SOK output goes to “1“ once per Synccycle;
otherwise the Synccycle should be increased.
Example:
Synccycle=4 x sampling time
Bus circulating time=2 x sampling time
Assumption:
The SYNPRO function block calculates at the center of the sampling
time (after all of the receive- and transmit blocks)
Sampling time
Synczyklus
Bus circulating
time
Output SOK
1
0
(1) (2) (3) (4) (1) (2)
SYNC_command
SYNC_quit
SYNC_command
(4)
Fig. 4-8 Timing diagram SYNC version 3
After the SYNC command has been initiated, the transmit- and receive
blocks are inhibited for three sampling times (one bus circulating time +
one sampling time) (SOK=0). The transmit- and receive blocks are
enabled in the fourth sampling time after the SYNC command has been
initiated (SOK=1).
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