Rt Classes; Rt Classes For Profinet Io - Siemens SINAMICS S150 Operating Instructions Manual
Converter cabinet units 75 kw to 1200 kw
Hide thumbs
Also See for SINAMICS S150:
- Engineering manual (530 pages) ,
- Manual (312 pages) ,
- Function manual (108 pages)
Table of Contents
Advertisement
Operation
6.8 PROFINET IO
6.8.4
RT classes
6.8.4.1
RT classes for PROFINET IO
Description
PROFINET IO is a scalable realtime communications system based on Ethernet technology.
The scalable approach is expressed with three realtime classes.
RT
The RT communication is based on standard Ethernet. The data is transferred via prioritized
Ethernet telegrams.
IRTflex (SW functionality planned for FW2.5 SP1)
The telegrams are sent cyclically in a deterministic cycle (Isochronous Real Time). In so
doing, the telegrams are exchanged in a bandwidth reserved by the hardware. One IRT time
interval and one standard Ethernet time interval are created for each cycle.
IRTtop
In addition to the bandwidth reservation, the telegram traffic can be further optimized by
configuring the topology. This enhances the performance during data exchange and the
deterministic behavior. The IRT time interval can thus be further optimized or minimized
compared with IRTflex.
In addition to the isochronous data transfer, with IRT even the application (position control
cycle, IPO cycle) can be synchronized in the devices. This is an essential requirement for
closed-loop axis control and synchronization via the bus.
Table 6-24
Comparison between RT, IRTflex and IRTtop
RT class
Transfer mode
MinDeviceInterval
Isochronous application
Start time of the isochronous
application
250
RT
Switching based on the MAC
address; prioritization of the
RT telegram possible using
Ethernet-Prio (VLAN tag).
Typically 2-8 msec
-
-
IRTflex
Switching using the MAC
address; bandwidth
reservation by reserving an
IRTflex interval in which only
IRTflex frames are
transferred but, for example,
no TCP/IP frames.
Typically 1 msec
-
The times for receiving the
data are not scheduled
exactly; only the start and
end of the interval are fixed.
Operating Instructions, 07/07, A5E00288214A
IRTtop
Path-based switching using
a topology-based planning;
no transmission of TCP/IP
frames in the IRTtop interval.
Fully deterministic, also for
250 µsec
Yes
Times for receving the data
scheduled exactly. A
synchronous application can
be started directly afterwards
(similar to DP).
Drive converter cabinet units
Advertisement
Table of Contents
