SEW Servo Motors – Mitchell Electronics Inc

Overview

There is a wide range of SEW servo motors on the market including both synchronous and asynchronous types. These servo motors will typically use a resolver as the default feedback sensor, however, they also have the option to equip incremental encoders or serial encoders like SICK Hiperface and SSI. This article will describe the most common synchronous servo motor configurations that we have documented and will include information for connection and testing.

Common synchronous SEW motor models types are CMP, CFM, DFS, and DFY, among others . Keep in mind that SEW will often include a "prefix" to the motor model which appears to be some type of unique customer or job code. This prefix of the motor model can be ignored when referencing support information in the article below.

Fig. 1: SEW CMP series motor nameplate with "prefix" model showing in red.

Common feedback test cables for SEW are the TI-5908 12 pin M23 resolver cable and the TI-5650 12 pin M23 SICK Hiperface cable, as well as many motors coming with terminal strip connection boxes.

We find most SEW servo motors use a standard alignment for both resolver and Hiperface feedbacks of

+U-V=60E and +U-W=120E. SEW does store memory data in the encoder when a Hiperface encoder is used. The memory data contains the motor model, serial, and other nameplate info but the alignment is standardized and not stored as a unique offset in the data. Our SEW Memory Test and Memory Program tools can be used to read and decode the original data, save it, and write to a replacement encoder if necessary.

Fig. 1: Example of the results from a Memory Test of a SEW CMP series motor

Feedback Type Identification

Most SEW servo motors will have a 4-digit code in the motor model that identifies exactly which feedback type is used. The breakdown below shows how the feedback identification is structured.

Feedback Type Codes

Rotary Encoders for Synchronous Servomotors

Motor Model Types and Breakdowns

BS(X)F Series

These motors will come equipped with a "HIPERFACE" multi-turn encoder.

Depending on the feedback model you could use one of our direct-to-encoder cables for feedback testing on the TI-5000JX.

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CFM Series

These motor have a resolver equipped as feedback device for default however they still have the motor option to equip a HIPERFACE multi-turn encoder.

The motor's connections could also vary depending on the contact assignments. Below you will find the different examples from the manual:

CFM Motor Power Connections

CFM Feedback Connections
Contact assignment of signal plug connector of encoder cable for Hiperface encoder AS1H/ES1H

For motors that come equipped with a Hiperface encoder our cable TI-5650 along with the module TI-5104 can be used for testing. However we have seen in some cases that they don't come with the 12 pin connector and the connection is done through a terminal box:

In the other hand the resolver's contact assignment of signal plug is similar to the hiperface encoder below you will find the pin assignment from the manual

Our cable TI-5908 is used for testing the resolvers that have the 12 pin M23 connectors.

In case the motor doesn't have a 12 pin connector for the Resolver below you will find the connection configuration from the terminal box:

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DFS Series

The motor's power and feedback cables are connected to a terminal block, the connection configurations are listed below as reference:

DSF56 Motor Power Connection

DFS56 Resolver/Encoder Connection

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DFY Series

This series of motors have the option of the electrical connection through a terminal box or plug connector, below you will find the different configurations.

DFY71...DFY112 Motors with Terminal Box