Communications
configuring
System- and communication configuring D7-SYS - SIMADYN D
3-269
Edition 12.2003
3.23.3.3
Assigning the copying relationships of the NTC to NTD
An NTC function block can be assigned to several NTD function blocks.
The NTC transfers a correctly logged-on channel to an NTD, which then
handles the actual data transport. The copying relationships (links) are
then consecutively transferred to the NTD function blocks. If all of the
NTDs were assigned a copying relationship (link), the first NTD is re-
selected. The NTD are handled in the sequence in which they were
logged-on. It does not make sense to configure those NTD function
blocks which are assigned to an NTC in different sampling times.
3.23.3.4 Route
selection and errors
If the NTC finds a network channel, it must first define a route to the
destination. Only the shortest route to the destination is considered. If
there are several "shortest" routes, up to four routes are checked. If a
channel cannot be logged-on up to the target node, this is not signalled to
the utility FB, as principally, a subrack could still be powered-up, whereby
a route would be possible to the destination.
If send- and receive channels have different channel modi or log-on
parts, then this is signalled to the sender and receiver using an
appropriate acknowledge index.
Network connections which have been established once, are kept, until
the subrack, on which the channel is physically located (i.e. that subrack,
which accommodates the CS12/13/14 module), is re-organized or
shutdown.
If a subrack is powered-down and powered-up again in operation,
existing network connections are automatically re-established.
3.23.3.5
Initialization of a rigid network
While the connection to a rigid network is being established, it is not
permissible that a subrack which accommodates a CS22 board, on which
a network connection is set-up fails. In this case, the associated
CS12/13/14 module must be re-organized.
3.23.3.6 Channel
modes
All four channel modi (handshake, refresh, select, multiple) are supported
in the rigid network. This has effects, especially for the "select" and
"multiple" modes: For several of these senders (select) or receivers
(multiple), these can be located on various subracks, without having to
have had channels being logged-on a multiple number of times. This is
explained in more detail in the configuring example for the network
status.