Siemens 6RA8085-6DS22

Descriptions of functions
10.35 CPU time load with SINAMICS DCM
SINAMICS DCM DC Converter
660 Operating Instructions, 12/2018, A5E34763375A
10.35.2
Computation examples
Example 1:
Project A is a single drive in a control cabinet. An AOP30 is located in the control cabinet
door. The motor has a pulse encoder, which is connected through the pulse encoder input
X177.41-48
Base load
70%
AOP30
+4
%
Internal encoder
+2%
Calculated CPU time load =
76%
Approx. 24% remain free for use by the free function blocks and/or DCC blocks.
Example 2:
Project B is a single drive connected to an S7 via PROFINET. 3 TM31 modules are used for
terminal expansion. The sampling rates of the TM modules (p4099) are set to 4000 ms. In
addition, a configured DCC application in the drive is running, which comprises 50 blocks
and runs in the 6 ms time slice.
Base load
70%
CBE20
+1%
3 × TM31 with p4099[1,2,3] = 500
+6
%
DCC application: 50 blocks @ 1 ms
+5%
Calculated CPU time load =
82%
The CUD is 82% utilized.
Note
The available CPU time can be expanded by equipping the SINAMICS DCM with a 2nd CUD
(right
-hand mounting slot). See Chapter "Expanding the SINAMICS DCM to include a
second CUD
(Page 628)".