3-9
ET 200U Distributed I/O Station
EWA 4NEB 812 6087–02b
If your ET 200U slave station has too many modules to fit into one tier, you
can expand your station to a maximum of four tiers with a maximum total of
16 bus units. As long as you stay within the limit of 16 bus units, it does not
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.
Interface Module
No. of Tiers
Connecting Cable
IM 315
Two
0.5 m (1.6 ft.) Permanently Connected to
Two Modules
IM 316
Three to Four
712–8 (Order No. 6ES5 712–8...)
Expand your station as follows:
4. Install an IM 315 or IM 316 interface module to the right of the last bus
unit on each tier.
5. If you are using IM 316 interface modules, use a 712–8 connecting cable
to connect the two modules and secure the connectors of the cable with
two screws each (see Figure 3-6).
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:
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)
When you select a cabinet, make sure that you choose one that can dissipate
enough heat to ensure proper functioning of your system. If necessary, use a fan.
To measure cabinet ventilation, determine the total power loss (heat dissipation)
as the sum of all typical power losses(heat dissipation) (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).
Expanding an
ET 200U Slave
Station to Several
Tiers
Mechanical and Electrical Configuration
