Siemens S7-300 - Nodes on the Subnet

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S7-300 Automation System, Hardware and Installation: CPU 312IFM - 318-2 DP
5-34 A5E00203919-01
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03,352),%86'3
These subnets are the most frequently used for S7-300 CPUs, so they are
discussed in detail below.
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In the following, all networked devices are referred to as nodes.
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A segment is a bus link between two terminating resistors. A segment can include
up to 32 nodes. It is also limited by the permitted line length, depending on the
transmission rate.
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These maximum transmission rates are possible:
• MPI
– 12 Mbps with CPU 318-2 DP
– 187.5 Kbps with all other CPUs
• PROFIBUS DP: 12 Mbps
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Maximum possible number of nodes per subnet:
Table 5-13 Nodes on the subnet
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Number 127 126
1)
Addresses 0 to 126 0 to 125
Remarks Default: 32 addresses
Reserved are:
• address 0 for PG
• address 1 for OP
of those:
1 Master (reserved)
1 PG connection (address 0 reserved)
125 slaves or other masters
1) Note the CPU-specific maximum specifications in the CPU manual.