Configuring Hardware and Communication Connections STEP 7.pdf

Configuring the Distributed I/O (DP)
Switching Between the DP Master System and the DP Slave in the Detailed View
of the Station Window
If you select the symbol for the DP master system ( ), all DP slaves
belonging to the DP master system will be displayed in the lower half of the station
window. If you select a DP slave symbol, the configuration of the DP slave is
displayed in the lower half of the station window. You can easily change between
displays by using the and buttons.
Slot Numbering in Distributed I/O Devices
Depending on which DP slave type you are configuring, the slots in the detailed
view of the DP slave begin either with "0" or "4."
With DP slaves that are configured by *.GSD files, the *.GSD file specifies at which
slot the I/O addresses start; the slots before that are "empty."
Slot numbering of DP slaves such as ET 200M that are completely integrated in
STEP 7 is derived from the structure of an S7-300 station according to the
following pattern:
Remarks on the slots of a DP slave, which is structured like the S7-300 station:
• The "actual" I/O (inputs/outputs) always starts with slot 4.
• Independent of whether a power supply module (PS) is inserted in the real
configuration or not: slot 1 is always reserved for a PS.
• Slot 2 is always reserved for the DP interface module.
• Slot 3 is always reserved for an expansion interface module (IM), independent
of whether a "real" I/O device can be expanded or not.
This pattern is used for all DP slave types: modular and compact. The slot
arrangement is important for evaluating diagnostic messages (the slot that triggers
diagnostics).
Configuring Hardware and Communication Connections with STEP 7
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