Data Structure Of The Uss Parameter Channel - Siemens Sinamics S110 Function Manual

Structure of the user data
The user data range of the USS protocol is used to transmit application data. This comprises
the parameter channel data and the process data (PZD).
The user data occupy the bytes within the USS frame (STX, LGE, ADR, BCC). The size of
the user data can be configured using parameters p2023 and p2022. The structure and
sequence of the parameter channel and process data (PZD) are shown in the figure below.
Figure 9-49
The length for the parameter channel is determined by parameter p2023 and the length for
the process data is specified by parameter p2022. If neither the parameter channel nor the
PZD are required, the relevant parameters can be set to zero ("PKW only" or "PZD only").
It is not possible to transfer "PKW only" and "PZD only" alternatively. If both channels are
required, they must be transferred together.
9.5.6

Data structure of the USS parameter channel

Description
The USS protocol defines for inverters the user data structure via which a master can access
the slave inverter. The parameter channel can be used to monitor and change any
parameters in the inverter.
Parameter channel
Process data can be edited and monitored (written/read) via the parameter channel, as
described below. The parameter channel can be set to a fixed length of 3 or 4 data words or
to a variable length.
The first data word always contains the parameter identifier (PKE) and the second contains
the parameter index.
The third, fourth and subsequent data words contain parameter values, texts and
descriptions.
Function Manual
Function Manual, 01/2011, 6SL3097-4AB10-0BP3
USS user data structure
Communication
9.5 Communication using USS
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