SIEMENS
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Siemens NC 62 · 2016
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SINAMICS S120 drive system
Communication
PROFINET
■
Design
(continued)
PROFINET IO with IRT for Motion Control
1)
In this case, a Motion Control system controls or synchronizes
axes using the PROFINET network. This requires cyclic, isochro-
nous data exchange with the drives. PROFINET IO with IRT
fulfills this requirement. The communication cycle is subdivided
into different, time-specific channels for this purpose. The first
channel is used for isochronous real-time communication (IRT),
followed by real-time communication (RT) and standard TCP/IP
communication. By appropriately configuring the application,
e.g. a synchronous relationship between axes, IRT telegrams
are implicitly determined and the appropriate configuration data
generated.
The optimum time sequence of the individual messages for each
network section is calculated with a special algorithm which
takes the topology into account. This means that the switch is
in a position to transfer the IRT telegrams without delay from
the input port to the defined output port and then to the target
device.
Transition from PROFIBUS to PROFINET
The functional interface between the controller and the
SINAMICS drives for PROFINET and PROFIBUS is defined
by the PROFIdrive V4 profile of PROFIBUS International. When
making a transition from PROFIBUS to PROFINET, the user
program does not have to be changed.
PROFINET with PROFIdrive
■
Design
(continued)
Motion Control concepts with PROFINET
With SINAMICS, PROFINET supports the implementation of
different automation structures. Distributed drive-based motion
control concepts or central architectures with a control are
supported in the same way as distributed automation solutions
with modular automation components.
PROFINET – interface on SINAMICS
•
SINAMICS S120 with CU320-2 DP Control Unit and
CBE20 Communication Board
The CU320-2 DP Control Unit on SINAMICS S120 is linked to
the PROFINET IO network via the CBE20 Communication
Board.
•
SINAMICS S120 with CU320-2 PN Control Unit
The CU320-2 Control Unit on SINAMICS S120 is linked to the
PROFINET IO network via the on-board PROFINET interface.
•
SINAMICS S120 with CU320-2 PN Control Unit and
CBE20 Communication Board
The CU320-2 PN Control Unit on SINAMICS S120 is linked to
the PROFINET IO network via the CBE20 Communication
Board.
•
SINAMICS S120 with CU310-2 PN Control Unit
The CU310-2 PN Control Unit on SINAMICS S120 is linked to
the PROFINET IO network via the on-board PROFINET inter-
face.
■
Function
Real-time communication with PROFINET IO
PROFINET uses standard TCP/IP for parameter assignment,
engineering and diagnostics. Real-time communication for the
transmission of process data is performed on the same line.
PROFINET IO has the following real-time features:
•
Real-Time (RT)
uses the option of prioritizing the communication stack of the
bus nodes. This permits high-performance data transmission
based on standard network components.
•
Isochronous real-time (IRT)
permits strict deterministic, cyclic data transmission with
extremely short response times and minimum jitter for high-
performance motion control applications. This feature is im-
plemented with a special ASIC, named ERTEC (Enhanced
Real Time Ethernet Controller), in the corresponding inter-
faces (switch integrated into device) or network components
(switch).
Automation with PROFINET
With these and other features, PROFINET fulfills all automation
requirements: Industry-compatible installation technology, real-
time capability, deterministic responses, integration of distrib-
uted field devices, simple network administration and diagnos-
tics, protection against unauthorized access, efficient vendor-in-
dependent engineering as well as isochronous motion control
applications.
PROFINET relies on switch technology and has expanded this
technology for real-time applications (IRT). This has the advan-
tage that the network topology can be optimally utilized and
adapted to the requirements of the machine. Collisions are
avoided and therefore optimum data flow rates achieved.
G_D211_EN_00053a
Standard
interval
IRT
interval
Cycle 1
Cycle 2
= cycle time
Cycle n
e.g. 1 ms position control cycle
Isochronous
communication
RT
communication
Standard
communication
TCP/IP data
RT data
IRT data
Standard
interval
IRT
interval
IRT
interval
PROFINET
PROFIdrive
G_D211_XX_00054a
1)
IRT interpolation with SINUMERIK NCK coming soon.
© Siemens AG 2016