2
Installation and Commissioning
26
CP 343−2 / CP 343−2 P AS−Interface Master
Release 08/2008
C79000−G8976−C149−04
Ground/Chassis Ground Concept
Notice
To achieve the noise immunity of the CP 343-2 / CP 343-2 P the AS and AS-i
power supply unit must be correctly grounded.
Please note the instructions regarding the grounding and chassis ground concept
in the SIMATIC S7 installation guidelines; see “SIMATIC S7 Automation System
S7-300 − Installation: installation manual” /4/.
2.2
Installing and Commissioning the CP
Installation
The CP can be installed in a SIMATIC S7-300 or an ET 200M.
Notice
The CP 343-2 / CP 343-2 P is not released for operation in the IM 153-3.
Step
Explanation / Meaning
Note
Only wire up the S7-300 with the power switched off!
Follow the steps as described in detail in /4/ when wiring between the power supply and the CPU.
1. Install the CP on the S7 standard rail.
Slots 4 to 11 are permitted for the CP in racks 0 to 3
(connected by IM 360/361).
Proceed as in the sections dealing with setup and
wiring, described in detail in /1/.
2. Establish the connection via the enclosed bus
connector to the backplane bus.
3. Then secure the CP by the screws in its casing.
4. Connect the AS-i cable to the terminals on the
front connector of the CP.
Contact is made at terminal pairs 17 and 19 or 18
and 20 of the front connector. Terminals 17 and 19
and terminals 18 and 20 are electrically connected
within the CP.
The assignment of the terminal pair and the polarity
are indicated on the front panel of the CP.
The second terminal pair (18/20) is intended for
connecting the AS-i power supply unit or a branch
of the AS-i cable. This allows the CP to be “looped”
into the AS-i cable. The AS-i power supply unit can,
however, be connected to any point on the AS-i
cable.