System Sampling Times; Features; Description - Siemens SINAMICS S120 Installation And Start-Up Manual

Basic Information about the Drive System

System sampling times

7.7 System sampling times
7.7.1

Features

The software functions installed in the system are processed cyclically at different
sampling times (p0115).
The sampling times (p0115) are always integer multiples of the basic sampling time
(p0110).
The basic sampling time and the sampling times for the functions are set automati-
cally when the drive unit is configured.
The settings are based on the selected mode (vector/servo), the number of con-
nected components, and the functions activated.
With the exception of the Active Line Module, all components connected via a
DRIVE-CLiQ socket on the Control Unit (DRIVE-CLiQ line) must be set to the
same basic sampling time (see p0111).
The sampling times of other components on the same DRIVE-CLiQ line must be
integer multiples of the sampling time of the Active Line Module (minimum: half the
sampling time of the Active Line Module).
7.7.2

Description

If the system sampling times are to be changed (e.g. to adjust the dynamic res-
ponse), the basic sampling time and the current controller sampling time (fastest
current controller sampling time) must always be the same.
The pulse frequency is entered in p1800 and must be an integer multiple of the
current controller sampling frequency. The minimum pulse frequency that can be
entered corresponds to half the current controller sampling frequency.
The basic sampling rate of a TMxx (p0111) is automatically set to the basic sam-
pling time of the DRIVE-CLiQ line used. The sampling times of the inputs/outputs
are entered in p4099 and must be a multiple of the basic sampling time (p0111).
Note
With a clock-synchronous PROFIBUS, the PROFIBUS DP clock cycle must be an
integer multiple of all three basic sampling times (p0110[0..2]).
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E Siemens AG, 2004. All rights reserved
SINAMICS S120 Installation and Start-Up Manual, 12/04 Edition