Acyclic Communication; General Information About Acyclic Communication - Siemens SINAMICS S120 Installation And Start-Up Manual

4.4

Acyclic communication

4.4.1

General information about acyclic communication

Description
With acyclic communication, as opposed to cyclic communication, data transfer
takes place only when an explicit request is made (e.g. in order to read and write
parameters).
The DPV1 services (read data set/write data set) are available for acyclic commu-
nication.
Note
Please refer to the following documentation for a detailed description of acyclic
communication via DPV1:
References:
The following options are available for reading and writing parameters:
S S7 protocol
This protocol uses the STARTER commissioning tool, for example, in online
mode via PROFIBUS.
S PROFIdrive parameter channel (DPV1) with data set 47
The DPV1 services are available for Master Class 1 and Class 2.
Properties of the DPV1 parameter channel
S One 16-bit address each for parameter number and subindex.
S Exchange of user data volumes up to 240 bytes.
S Concurrent access by several PROFIBUS masters (master class 2, e.g.
commissioning tool).
S Transfer of different parameters in one access (multiple parameter request).
S Transfer of complete arrays or part of an array possible.
S Only one parameter request is processed at a time (no pipelining).
S A parameter request/response must fit into a data set (max. 240 bytes).
E Siemens AG, 2004. All rights reserved
SINAMICS S120 Installation and Start-Up Manual, 12/04 Edition
/P5/ PROFIdrive Profile Drive Technology
Communication via PROFIBUS
Acyclic communication
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