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Siemens TX-I/O Engineering and installation guide CM110562en_13
Building Technologies Principles of electrical design 2019-05-15
For field devices requiring a supply other than DC 24 V, the bus includes a separate
conductor (24V~ / V
). The return is via ⊥ (system neutral).
The admissible current is max. 6 A.
This conductor can be supplied in one of two ways:
– with AC 24 V from a bus interface module or a power supply module.
This voltage is protected in the bus interface module / power supply module by a
10 A fine-wire fuse.
– with AC / DC 12 … 24 V from a bus connection module.
This voltage is protected in the bus connection module by a 10 A fine-wire fuse.
The 24V~ conductor (power supply module) / V
(bus connection module) is only
accessible on the bus connector to the right; it does not exist on the left side. This
means that within the same I/O row, several groups of modules can be formed, each
with a different field device supply, without having to interrupt the remaining bus
conductors (bus signal CD and module supply CS).
On a given I/O row, a new field device supply is required
– when the maximum power of the original field device supply (6 A) is reached, and
– whenever a group of I/O modules requires a different voltage or its own fuse.
Field device supply