Siemens SINAMICS S120 Function Manual page 529

All cyclic data are transferred within the send cycle. The actual send cycle that can be set
depends on various factors:
● Bus load
● Type of devices used
● Computing capacity available in the IO controller
● Send cycles supported in the PROFINET devices assigned to a synchronization domain.
The table below specifies the reduction ratios which can be set between the send cycle and
the update cycles for IRT*, IRT "high performance", IRT "high flexibility" and RT.
Table 10- 47 Settable send cycles and update cycles
Send cycle
Range 250, 500,
"even" 1000 µs
1)
2000 µs
4000 µs
Range 375, 625, 750,
"uneven" 875, 1125,
3)
1250 µs ...
3875 µs
(increment
125 µs)
Note
There is no intersection between the send cycles for the "even" and "uneven" ranges!
Explanations for the above table:
1) It is only possible to set send cycles from the "even" range when IO devices with RT class
"RT" are assigned to a synchronization domain. Likewise, only the reduction ratios from the
"even" range can be set for a send cycle setting from the "even" range.
2) It is generally only possible to set a reduction ratio of 1:1 between the update and send
cycles for IO devices (ET200S IM151-3 PN HS, SINAMICS S) which are operated in
isochronous mode. In this case, the update cycle mode must always be set to "fixed factor"
(under I/O device properties, "IO cycle" tab, "Mode" pulldown menu). This means that STEP
7 will not automatically adjust the update cycle and thus the update cycle will always
correspond to the send cycle.
3) The send cycles from the "uneven" range can be set only if a synchronization domain
does not include any IO devices with RT class "RT". Likewise, only the reduction ratios from
the "uneven" range can be set for a send cycle setting from the "uneven" range.
Drive functions
Function Manual, (FH1), 10/2008, 6SL3097-2AB00-0BP5
1 ms is an example of a typical send cycle.
Reduction ratio between update and send cycles
RT
IRT "high flexibility"
1,2,4,8,16,32,64,128,256,512
1,2,4,8,16,32,64,128,256
1,2,4,8,16,32,64,128
not supported 5)
Communication PROFIBUS DP/PROFINET IO
10.3 Communication via PROFINET IO
IRT*
IRT "high performance"
4)
IRT*: 1
IRT "high performance": 1,2,4,8,16
IRT*: 1
IRT "high performance": 1,2,4,8,16
IRT*: 1
IRT "high performance": 1,2,4,8,16
1
2)
2)
2)
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