SIEMENS SINAMICS S120 Servo Drive System Application Guide

SIEMENS SINAMICS S120 Servo Drive System Application Guide: Complete Technical Analysis from Configuration to Optimization

In the field of modern industrial automation, motion control and servo drive technology are the core of achieving precision mechanical motion. The Siemens SINAMICS S120 series drive, as a high-performance representative of the Siemens drive family, occupies an important position in single axis and multi axis drive applications with its modular design, high-precision control, and powerful functional integration. This article aims to systematically introduce the composition architecture, project configuration process, basic debugging methods, motor optimization strategies, basic positioning functions, and communication implementation methods of the SINAMICS S120 drive system, providing a comprehensive and professional technical reference for drive system engineers.

Overview of SINAMICS S120 Drive System

SINAMICS S120 is a multi axis drive system that integrates V/F control, vector control, and servo control, capable of meeting the increasing number of axes and high-performance control requirements in industrial applications. According to different application scenarios, the S120 driving system is mainly divided into two structural forms: single axis AC/AC driver and multi axis DC/AC driver.

1.1 AC/AC Single Axis Drive

AC/AC single axis drive integrates the power module and motor module into one, commonly known as SINAMICS S120 single axis AC drive. It can achieve high-precision control of ordinary three-phase asynchronous motors, asynchronous servo motors, synchronous servo motors, torque motors, and linear motors. The core components of this driver include a control unit (CU310 DP or CU310 PN) and a power module (PM340). The control unit is connected to the power module through the PM-IF interface, and all DRIVE CLiQ components exchange high-speed data through a dedicated interface. Users can use the basic operation panel BOP20 for parameter settings and diagnostics.

1.2 DC/AC Multi Axis Drivers

The DC/AC multi axis drive adopts a common DC bus structure, which separates the power module from the motor module. The power module rectifies three-phase AC power into 540V or 600V DC power, and multiple motor modules share this DC bus. This structure is particularly suitable for multi axis control systems in industries such as papermaking, packaging, textiles, printing, and steel. Its advantage is that energy sharing can be achieved between each axis, and the wiring is simple and easy to expand.

The core control unit of the SINAMICS S120 multi axis drive system is CU320, which can control up to 6 servo axes or 4 vector axes in speed control mode. The main components of the system include:

Control unit (CU320): responsible for controlling and coordinating all modules, completing closed-loop control of current loop, speed loop, and position loop.

Power module: divided into basic type (BLM, no feedback function), intelligent type (SLM, rectification feedback unit), and active type (ALM, adjustable DC bus voltage).

Motor module: also known as inverter unit, divided into single axis and dual axis modules.

Sensor module: Convert encoder signals into signals recognizable by DRIVE CLiQ.

24V DC power module: supplies power to the system control part.

All modules are interconnected through a high-speed drive interface DRIVE CLiQ, forming a highly integrated modular system.

1.3 System status indication

Each module of SINAMICS S120 is equipped with LED indicator lights to reflect the real-time operation status of the equipment. For example, if the RDY indicator light of control unit CU320 is constantly green, it indicates that the module operation is ready and DRIVE CLiQ communication is normal; The constant red light indicates the presence of a fault; The constant orange light indicates that DRIVE CLiQ communication has been established. The READY and DC LINK indicator lights of the power module and motor module also provide critical operating status and fault information for quick on-site diagnosis.

Project configuration: offline and online modes

The debugging of SINAMICS S120 is completed by creating a project, which can be done in two ways: offline configuration and online configuration. Regardless of the method used, the prerequisite preparation work includes: preparing a PC with SCOUT software installed, connecting the hardware, and setting the DP address.

2.1 Offline Project Configuration

Offline configuration is suitable for Siemens standard motors or third-party motors without DRIVE CLiQ interface. All project data is manually entered offline and downloaded to the driver device after configuration is complete. The specific steps are as follows:

Create a new project: Create a new project in SCOUT software, set the project name and storage path.

Set DP communication port: Set the communication port through Set PG/PC Interface and configure the baud rate (default is 1.5Mbps or 12Mbps). Use the Diagnostics function to test whether the DP card is working properly and read the station numbers of all workstations to ensure that the programmer can access the driver device.