Siemens SINAMICS Series Operating Instructions Manual page 503

Modules
The following S110/S120 modules support the IRT "high performance":
● S120 CU320 together with the CBE20
● S120 CU320-2 DP together with the CBE20
● S120 CU320-2 PN
● S120 CU310 PN
● S120 CU310-2 PN
● S110 CU305 PN
Comparison between RT and IRT
Table 10- 36 Comparison between RT and IRT
RT class
Transmission mode
Isochronous application in
the IO controller
Determinism
Reload the network
configuration after a change
Maximum switching depth
(number of switches in one
line)
For possible send cycles, see subitem "Send cycles and update cycles for RT classes" in table "Adjustable send cycles
and update cycles"
Set the RT class
The RT class is set by means of the IO controller interface properties. If RT class IRT "high
performance" is set, it is not possible to operate any IRT "high flexibility" devices on the IO
controller and vice versa. IO devices with RT can always be operated, regardless of the IRT
class setting.
SINAMICS DCM DC Converter
Operating Instructions, 12/2018, A5E34763375A
RT
Switching based on the MAC
address; prioritization of the
RT telegrams possible using
Ethernet-Prio (VLAN tag)
No
Variance of the transmission
duration by started TCP/IP
telegrams
Not relevant
10 at 1 ms
10.5 Communication via PROFINET IO
IRT "high flexibility"
Switching using the MAC
address;
bandwidth reservation by
reserving an IRT "high flexi-
bility" interval in which only
IRT "high flexibility" frames
are transferred but, for
example, no TCP/IP frames.
No
Guaranteed transmission of
the IRT "high flexibility" tele-
grams in the current cycle by
the reserved bandwidth.
Only when the size of the
IRT "high flexibility" interval
needs to be modified
(reservation of position is
possible).
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Descriptions of functions
IRT "high performance"
Path-based switching
according to a topology-
based plan; no transmission
of TCP/IP frames and IRT
"high flexibility" frames in the
IRT "high performance"
interval.
Yes
Exactly planned transfer;
times for transmission and
receiving are guaranteed for
any topologies.
Always when the topology or
the communications
relationships change.
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