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Building Technologies Division
User Manual RWF55...
CC1U7867en
Infrastructure & Cities Sector
12 Profibus-DP interface
05.11.2013
Protection functions
Threshold monitoring for DP slaves
Access protection for inputs/outputs of DP slaves
Monitoring of user data traffic with adjustable monitoring timer for DP master
Device types
DP master class 2, e.g., programming/configuration devices
DP master class 1, e.g., central automation devices such as PLC, PC, etc.
DP slave, e.g., devices with binary or analog inputs/outputs, controllers, recorders,
etc.
Data traffic between the DP master and DP slaves is automatically processed by the
DP master in a fixed, constantly recurring order. The user specifies the assignment of a
DP slave to a DP master during bus system configuration. The DP slaves to be
included in or excluded from cyclical user data traffic are also defined.
The data traffic between the DP master and DP slaves is divided into parameter
setting, configuration, and data transfer phases. Before a DP slave is included in the
data transfer phase, the DP master checks (in the parameter setting and configuration
phase) whether the desired configuration that has been configured matches the actual
device configuration.
As part of this check, the device type, format information, and length information as well
as the number of inputs and outputs must match. As a result of this, the user is
provided with reliable protection against parameter setting errors. As an addition to the
user data transfer function that the DP master performs automatically, it is also possible
to send new parameter setting data to the DP slaves if requested by the user.
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Call telegram
Closing information
Basic data
Head information
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Head inform
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Input data
Closing info
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Respons
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Figure 40: User data transfer with Profibus DP
Cyclical data traffic