Computation Examples - Siemens SINAMICS DCM Operating Instructions Manual

Descriptions of functions
10.31 CPU time load with SINAMICS DCM
Note
The capacity of the SINAMICS DCM can be expanded by equipping the SINAMICS DCM
with a 2nd CUD (right-hand slot). See the "Expanding the SINAMICS DCM to include a
second CUD" chapter.
10.31.2

Computation examples

Example 1:
Project A is a single drive in a control cabinet. An AOP30 (PPI) is located in the control
cabinet door. The motor has an incremental encoder, which is connected through the
internal encoder input.
Base load
AOP30 via PPI
Internal encoder
Calculated CPU time load =
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
CBE20
3 × TM31 with p4099[1,2,3] = 500
DCC application: 50 blocks @ 1 ms
Calculated CPU time load =
The CUD is 82 % utilized.
Note
The available CPU time can be expanded by equipping the SINAMICS DCM with a 2nd CUD
(right-hand slot). See the "Expanding the SINAMICS DCM to include a second CUD"
chapter.
498
70 %
+4 %
+2 %
76 %
70 %
+1 %
+6 %
+5 %
82 %
Operating Instructions, 1.2012, C98130-A7066-A1-05-7619
SINAMICS DCM DC Converter