Siemens SIMOTRAS 6SG7050, Operating Instructions Manual

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01.04 Start-up
SIEMENS AG 6SG7000-0BA76
7-49
SIMOTRAS HD Operating Instructions
Apart from these data, a SIMOLINK master can also send special telegrams with application-
specific data (addresses 201 to 204 and channel number 0). An SLB as dispatcher does not
support these special telegrams.
If a transceiver stops receiving telegrams due to an interruption, it automatically transmits special
telegram "Time Out“.
The transmission rate is 11 Mbits/s . The data telegrams are transmitted in direct succession,
followed by a SYNC telegram and a pause telegram, within one bus cycle. Transferring the data
telegrams without pauses ensures a higher data throughput. At a data transmission rate of 11
Mbit/s, the transmission time for one telegram is 6.36
µ
s.
. . .
Bus cycle
Data telegrams
Break SYNC
The assignment of telegrams to nodes is determined by the type of SIMOLINK application, i.e.
peer-to-peer functionality or master-slave functionality.
When an SLB is configured as the dispatcher, only the peer-to-peer functionality is available.
Peer-to-peer functionality
In this mode, there is no defined logical master for distributing information. The drives have equal
status in logical terms and exchange data with one another via the ring bus. One node (SLB)
specifies the bus cycle in its dispatcher role to keep the transmission alive. All nodes receive and/or
send user data. Dispatcher and transceivers can read any telegram, but may only write information
in the telegrams specifically assigned to them (node address = address in telegram).
Master-slave functionality
A logical master (e.g. SIMATIC) supplies all nodes with information on the one hand and, on the
other, specifies the bus clock cycle (dispatcher function). All other nodes behave as described
above under peer-to-peer functionality, i.e. they receive and/or send user data, but are only
permitted to read or write telegrams containing their address.
In contrast to peer-to-peer functionality, the restrictions described above (no gaps in address
sequence, uniform number of used channels, no special data) do not apply. The master has its own
8 channels for transferring data, but can also use telegrams with the address and channel numbers
of the transceivers for its data transmissions.
NOTE
An external 24V power supply to the SIMOLINK modules ensures that communication with the
other bus nodes continues if a device fails.
However, this power supply does not prevent the short interruption in communication when the
device is switched on again when establishing communication is forced.