Lenze · I/O system 1000 · Reference Manual · DMS 5.0 EN · 09/2016 · TD17 216
6 PROFIBUS communication
6.2 System configuration
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6.2 System configuration
6.2.1 Device types
PROFIBUS differentiates between active nodes (master) and passive nodes (slave).
Class 1 master (DPM 1)
A class 1 master (DPM 1) is a central control which exchanges data with the slaves in a fixed cycle.
Typical DPM 1 are, for example, PLC or PC. Via an active bus access, measured data is read cyclically
from the input modules of the slaves and setpoints are written to the output modules of the slaves.
Class 2 master (DPM 2)
Class 2 masters (DPM 2) are used for engineering, configuration or operation. During
commissioning, maintenance and diagnostics, for example, DPM 2 can be used to configure the
connected slaves, evaluate measured values and parameters and query the status of the slaves. The
data is transmitted acyclically. DPM 2 do not have to be permanently connected to the bus. DPM 2
are provided with active bus access.
Slave
Slaves are peripherals (PROFIBUS bus couplers) making process information (input data and output
data) available. Slaves only respond to direct requests by the master.
6.2.2 Mono master system
[6-1] PROFIBUS-DP Mono master system
In case of mono master systems, only one master is active on the bus during the operating phase of
the bus system. The slaves are connected in a decentralised way to the master via the transmission
medium. This system configuration serves to achieve the shortest bus cycle time.
Master
(DPM 1)
Slave 1 Slave 2 Slave 3
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