Communications
configuring
System- and communication configuring D7-SYS - SIMADYN D
3-51
Edition 12.2003
•
Synccycle
Synccycle is a multiple integer of the sampling time. It can be
configured at input CNX of function block SYNPRO.
(Synccycle=CNX x sampling time).
A Synccycle always starts with a sampling time. A synchronizing
command is always initiated by the SYNPRO function block in the
system mode at the start of a sampling time.
Configuring version 1 corresponds to most of the applications:
•
Generating SYNC commands.
•
The data consistency over all slaves is guaranteed.
•
The Synccycle is at least twice as long as the sampling time (CNX>1).
−
the length of the transmit telegrams (outputs) for each slave may
not be greater than 32 bytes.
−
all transmit blocks and the SYNPRO function block must be
configured in the same sampling time.
−
the SYNPRO function block must be configured before all of the
transmit blocks (sequence of execution).
−
output SOK of function block SYNPRO must be connected with the
enable inputs of all transmit blocks (belonging to a slave group).
−
the bus circulating time must be shorter than the Synccycle minus
1 x sampling time. When operational, it should be checked as to
whether the SOK output goes to “1“ once in each Synccycle,
otherwise the Synccycle should be increased.
Example:
•
Synccycle=3 x sampling time
•
Bus circulating time=2 x sampling time
•
Assumption: The SYNPRO function block calculates at the center of
the sampling time (before all transmit blocks)
Sampling time
Synczyklus
Bus circulating
time
Output SOK
1
0
(1)
(2)
(3)
(1)
(2)
(3)
SYNC_command
SYNC_quit
SYNC_command
SYNC_quit
SYNC_command
Fig. 3-15
Timing diagram, SYNC version 1
Configuring
version 1
