Rules For Designing A Subnet - Siemens SIMOTION C230-2 Equipment Manual

Networking
Rules for the PROFIBUS addresses
Observe the following rules before assigning PROFIBUS addresses:
S All PROFIBUS addresses in a subnet must be different.
S The highest PROFIBUS address of a subnet must be w the greatest possible
PROFIBUS node address of this subnet.
Recommendation for PROFIBUS addresses
Reserve the PROFIBUS address "0" for a service PG and "1" for a service
SIMATIC HMI device which will be connected to the subnet if required.
Recommendation for the PROFIBUS address of the C230-2 for an exchange
or a service call:
Reserve the address "2" for a C230-2. This way, you avoid any occurance of
doubled addresses after installation of a C230-2 with the default setting into the
subnet (for example, when exchanging a C230-2). This means that you will assign
other nodes in the subnet an address higher than "2".
7.1.2

Rules for designing a subnet

Segment
A segment is a bus line between two terminating resistors. A segment with C230-2
as master can contain up to 32 slaves. A segment is also limited by the permissi-
ble length of the cable as a function of the baud rate (see Subsection 7.1.3).
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E Siemens AG, 2003 All rights reserved
SIMOTION C230-2, 04.2003 Edition