Siemens SITRANS T3K PA, Instruction Manual

Page: 112 / 130

Instruction Manual 7NG3213
112
SITRANS T3K PA
C79000-B7174-C55-04
!
WARNING
Only certified supply units (DP/PA coupler or DP/PA link may be used
to feed the intrinsically safe PROFIBUSes. The requirements can be
found in the EC-type examination certificate (see chapter 6.2, page
97).
The number of devices which can be connected to a bus channel can be
determined from the maximum current consumptions of the connected devices
(according to standard
≥
10 mA per device) and the available current. A current
reserve should be planned for safety reasons otherwise there is a risk that a
defective device overloads the bus due to increased current consumption and the
power supply and communication with all undisturbed users could break down.
The size of the reserves depends on the current increase in the event of an error
specified by the manufacturer.
Every device has its own address to be able to distinguish it from all the others.
The address setting is described in the chapter 3, page 88.
You will find further information about components, installation regulations and
configuration in the System Description Field Technology, see appendix 3, page
117 ”Literature and Catalogs” /2/.