Siemens SIMATIC S5 ET 200U Manual page 42

Expanding an
If your ET 200U slave station has too many modules to fit into one tier, you
ET 200U Slave can expand your station to a maximum of four tiers with a maximum total of
Station to Several
16 bus units. As long as you stay within the limit of 16 bus units, it does not
Tiers matter how many bus units are installed in one tier. To connect the tiers to
each other, you need one interface module IM 315 or IM 316 per tier.
You install the interface modules that connect the tiers as follows:
1. Hang the module on standard mount. rail to the right of the last bus unit.
2. Swing the module back until the slide on the module snaps into place.
3. Connect ribbon cable from interface module to the last bus unit in the tier.
You must choose between two interface modules to connect the tiers of your
multi–tier configuration, depending on how many tiers you have. The follow-
ing table compares the two types of interface modules.
IM 315
IM 316
Expand your station as follows:
4. Install an IM 315 or IM 316 interface module to the right of the last bus
5. If you are using IM 316 interface modules, use a 712–8 connecting cable
Make sure that you include at least 210 mm (8.3 in.) net clearance between
the tiers (see Figures 3-6 and 3-7).
Figure 3-6 shows a multi–tier configuration using IM 316 interface modules
in a cabinet. Cabinet installation can be necessary under following conditions:
When you select a cabinet, make sure that you choose one that can dissipate
enoughheatto ensureproperfunctioningof your system.If necessary, usea fan.
To measurecabinetventilation,determinethetotalpowerloss(heatdissipation)
asthesumof alltypicalpowerlosses(heatdissipation) (see Catalog ST 52.1).
To ensure interference immunity, install your ET 200U slave station on a
metal plate. If this is not possible, you must at least connect the standard
mounting rails to each other using a low resistance conductor. You can also
use mounting plates of the 8LW or 8LX systems (see Catalog NV 21).
You can also install the standard mounting rails vertically so that the modules
are installed on top of each other. In such an arrangement, heat dissipation
through convection is less than in a horizontal configuration. For this reason,
the permissible ambient temperature is limited to 40 C (104 F).
ET 200U Distributed I/O Station
EWA 4NEB 812 6087–02b
Interface Module No. of Tiers
Two
Three to Four
unit on each tier.
to connect the two modules and secure the connectors of the cable with
two screws each (see Figure 3-6).
In danger of coming into contact with live parts (e.g., supply terminals)
When environmental conditions are harsh (e.g., dust, splashing water,
corrosive gases and vapors)
Mechanical and Electrical Configuration
Connecting Cable
0.5 m (1.6 ft.) Permanently Connected to
Two Modules
712–8 (Order No. 6ES5 712–8...)
3-9