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Siemens TX-I/O Engineering and installation guide CM110562en_13

Building Technologies Principles of electrical design 2019-05-15

10.6.7 Installation examples for island bus expansion

• In the installation examples, the island bus length is the same on both side of

the island bus expansion (1/2 Lmax). Concerning Lmax, please refer to page 81.

• Permissible power changes when other lengths are selected (see rule 21).

< 200 m

< 1/2 Lmax

< 1.2A

10562z154

< 1.2A

< 1/2 Lmax

< 1.2A

< 1/2 Lmax

< 1.2A

< 1/2 Lmax

< 1.2A

< 1/2 Lmax

< 200 m< 200 m< 200 m

< 200 m

• Example P illustrates (versus example A) that power can be doubled thanks cutting

the length of the island bus in half (1/2 Lmax, Rule 21 / 22, page 92)

(1.2A instead of 0.6 A in the remote I/O row).

• Example Q illustrates

– (versus example P), for each sub-island, the island bus length "1/2 Lmax" is once

again allowed.

– the length of the island bus expansion segment (max. 200 m) can be distributed

as desired on decentralized sub-islands (in extreme cases 198 + 1 + 1 m,

1 + 198 m + 1 or 1 + 1 + 198 m).

STOP

Note!

Notes