Sampling Times And Number Of Controllable Drives - Siemens SINAMICS RAILCTRL Function Manual

Function description

5.7 Sampling times and number of controllable drives

5.7 Sampling times and number of controllable drives
Note
Information on the system sampling times and the number of drives that can be controlled can
be found in the following reference:
● SINAMICS S120 Drive Functions Function Manual, Chapter "System control, sampling
times and DRIVE-CLiQ wiring".
The remaining computation time (see r9976) can be used for RAILCTRL and other options (e.g.
DCC).
Examples of additional computation time utilization
The following table lists the values for the additional CPU time utilization for SERVO drive
objects with activated RAILCTRL Technology Extension and activated CU communication:
Table 5-5 RAILCTRL for SERVO drive object computation time utilization (examples)
Example Current controller sam‐
pling time
p0115[0]
1 125 µs
2 250 µs
For deactivated CU communication, the additional computation time utilization for SERVO
drive objects compared with the listed values decreases as follows:
● With current controller sampling time = 125 µs, the computation time utilization is 24.3 %
less (12.1 % per communication direction).
● With current controller sampling time = 250 µs, the computation time utilization is 12.8 %
less (6.4 % per communication direction).
For 4 drives with servo control (p0115[0, 1] = 125µs) and infeed unit (p0115[0] = 250 µs),
RAILCTRL can be operated with a sampling time of 125 µs for all SERVO drive objects.
The current controller sampling time must be set the same for all drive objects, as the segment
transition control for RAILCTRL is calculated in each sampling time. This is also recommended
for all drive objects on the same CU, which do not use RAILCTRL.
Note
If you use the RAILCTRL Technology Extension on a Control Unit, in addition to the SERVO
drive objects and the Technology Extension, it is not permissible that you create a VECTOR
drive object.
42
Additional CPU time utilization (r9976[1])
2 SERVOs 3 SERVOs
with RAILCTRL with RAILCTRL
Approx. 35.0 % Approx. 39.2 %
Approx. 19.0 % Approx. 21.4 %
4 SERVOs 6 SERVOs
with RAILCTRL with RAILCTRL
Approx. 43.4 %
Approx. 23.9 % Approx. 28.7 %
Function Manual, 09/2019, A5E38120767B
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RAILCTRL