Siemens SINAMICS DCM Manual page 476

In contrast to standard Ethernet and PROFINET IO with RT, the telegrams for PROFINET IO
with IRT are transferred according to a schedule.
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 configu-
ration 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"
SINAMICS DCM DC Converter
Operating Instructions, 02.2015, A5E34763375/RS-AA/001
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
ac.maher.co.ir
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 ex-
ample, 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 (reser-
vation of position is possi-
ble).
61
Descriptions of functions
IRT "high performance"
Path-based switching ac-
cording 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 relation-
ships change.
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