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NETLink PRO ETH
5.1.2
Bus settings
The NETLink PRO ETH can be operated on three different bus systems:
PPI, MPI and PROFIBUS
From the NETLink PRO ETH user’s viewpoint, the three bus systems only
differentiates by the transmission rates that can be selected and the additional
options which are explained here.
The bus configuration is passed to the NETLink PRO ETH during the
runtime of the NETLink PRO driver and is not stored in the device
(exception: enabling the RFC1006 functionality, see Section 8).
It is possible to use the NETLink PRO ETH without specifying bus-related
information. The NETLink PRO ETH then automatically ascertains the bus
parameters and can be operated on different programmable controllers,
possible, with different transmission rates without switching over the
NETLink PRO driver.
This autobaud function is supported if the ‘
Cyclic distribution of the bus
parameters
’ function is activated in the participating programmable
controller. Usually this functionality is not available at S7-200 systems.
CPUs still exist, usually older types, that do not support cyclic distribution of
bus parameters. The autobaud functionality cannot be used on these CPUs.
5.1.2.1 MPI configuration
The MPI configuration contains station and network-related settings.
The most important setting concerning bus configuration is assignment of
the station address. This refers to the address the NETLink PRO ETH will
have on the bus when it goes online.
The station address can have any value from ‘
0’
and ‘
126’
if the selected
address is lower than or equal to the highest station address (HSA).
Example: HSA = 31
Any value between ‘
0
’ and ‘
31’
can be specified for the station address if
this address does not yet exist on the bus.
The local timeout of the NETLink PRO driver can be parameterized in the
station-related settings. If the driver does not receive a response to a request
within the set timeout, a communication error is signaled to the Simatic
application.
In the network-related settings, the transmission rate must be selected, as
must the HSA of the programmable controller to be addressed.
