User Manual

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Siemens TX-I/O Engineering and installation guide CM110562en_13
Building Technologies Principles of electrical design 2019-05-15
For earthing rules, refer to section 6.4.1, for wiring examples refer to section 10.6.6
13. Only a line topology is permitted with the island bus expansion.
14. Per sub-island a maximum of one island bus expansion module is permitted.
15. No cascading (i.e. no connection from a decentralized sub-island to another
decentralized sub-island).
16. One I/O island can consist of one local sub-island and up to 8 decentralized sub-
islands.
17. For island bus wiring in sub-islands (local and decentralized), the rules as descri-
bed in Section 10.6 apply, with the exception of distances Lmax, see rule 21.
18. Tools (XWP, DTS, etc.) and operator units (PXM...) can only be connected to the
local sub-island (where the master of the island bus expansion is located).
19. The admissible length of the island bus expansion is 400 m.
20. The maximum distance between the local sub-island (B) and the most distant
decentralized sub-island (F) must not exceed 200 m.
Key
= I/O row with AS
or BIM
= I/O row
= cable island bus
expansion
= do not add distance
= cable island bus
= add distances
B...G see glossary, page 91
10562z144_01
1/2 Lmax
1/2 Lmax
1/2 Lmax
200 m 200 m
3/4 Lmax
1/4 Lmax
200 m 200 m
200 m 200 m
3/4 Lmax
1/4 Lmax
1/4 Lmax
3/4 Lmax
B
C
FF
G G
G G
FF
FF FF
FF FF
B
B
G G
G G
C
G G
G G
C
21. The length must be counted on both sides of the expansion for the island bus.
The sum total may not exceed Lmax per Section 10.5.
(Installation examples in Section 10.6.7 only deal with the case ½ Lmax).
22. The power can be increased proportionally or the wiring cross section
reduced since the island bus per sub-island is shorter than Lmax.
23. For TX-I/O modules series B and P-Bus-BIM series A, only 1/4 Lmax is
permitted for the sum total.
Reason: The island bus circuits for these devices are not optimized for island bus
expansion.
Earthing rules
Topology rules
Maximum wire lengths
for island bus expansion
Max
imum wire length
for island bus