NORD Drivesystems BU0050 - Manual (Page 7)

1.1 USS - General information
BU 0050 GB-3111 Subject to technical amendments 7
Foreword
This supplementary documentation is valid for the SK 300E, SK 500E, SK 700E series and for the SK 750E.
It describes the setup of communication via RS485.
For this, the main emphasis is on communication according to the USS protocol. Corresponding optional
modules are available for the SK 700E and SK 750E series. The SK 300E and SK 500E series have an
appropriate interface integrated as standard.
In addition, the requirements of Modbus communication (SK 540E and higher) will be considered.
1 USS
1.1 General information
1.1.1 The USS Protocol
With the aid of the USS protocol, a user can set up a serial bus coupling between a higher level Master and
several slave systems. Master systems can for example be memory programmable control units (SPS) or
PCs.
The USS protocol allows the user to implement automation tasks with conveying according to time-cycled
telegram traffic (

fixed telegram length required), as well as visualisation tasks.
The USS protocol is a simple, serial transfer protocol defined by Siemens, which if fully tailored to the needs
of drive technology.
1.1.2 Features
Support of a multiple point coupling, e.g. EIA RS 485 hardware or a point-to-point coupling, e.g. EIA RS 232.

Master / Slave access procedure

Single Master System

Maximum 32 participants (maximum 31 slaves)

Simple, secure telegram framework

Same physical bus design as PROFIBUS (DIN 19245 Part 1)

The data interface to the basic device is according to the PROFILE for variable speed drives.
This means that with USS, the information to the drive unit is transferred in the same way as with the
PROFIBUS-DP.

Can be used for commissioning, service and automation

Service tools on PC (NORD CON)

Simple to implement in customer-specific systems-
1.1.3 Delivery
Check the equipment immediately after delivery/unpacking for transport damage such as deformation or
loose parts.
If there is any damage, contact the carrier immediately and carry out a thorough assessment.
Important! This also applies even if the packaging is undamaged.