FERTIGUNGS- & MASCHINENAUTOMATION

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01 Sendix S36: Compact motor feedback systems in 36.5 mm size for all power ranges – reduce the number of motor variants, standardize the mechanical installation

Future-proof motor feedback systems

Compactness, efficiency and performance are the omnipresent requirements of

the machinery and plant engineering industry. This applies to the drives

technology too.

With its new motor feedback systems, Kübler offers drive manufacturers a future-proof and flexible sensor solution. They are based on a platform that allows reducing the number of motor variants and standardizing the mechanical installation and covers a wide range of electrical interfaces.

Text: Michael Scalet

ompanies today strongly invest in research

and development in order to be able to offer in the future optimal solutions for the IIoT. One of their goals is

to shape the future with new technologies for digitization

and networking. Machinery and plant operators

increasingly demand preventive maintenance by means of

intelligent data analysis. This will allow them increasing

further the availability and reliability of their production

SPS IPC Drives ↗Kübler: Hall 7A Stand 506

plants. Intelligent sensors allow fast error diagnosis, which

contributes to the reduction of unscheduled downtimes

and production outages. The drive manufacturers confront

this task with the development of smart motor concepts.

Trends in drive technology

The communication between a motor feedback system and

the drive controller can be a decisive factor for the

performance of the drive system. This applies in particular

in case of dynamic axes, smooth speed control and high

positioning accuracy. -

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So far, the choice of the components was often imposed

by the proprietary interfaces and not by the requirements

placed on the application. This is now counteracted by the

trend according to which drive manufacturers are

increasingly following a second-source strategy in order to

minimize costs and risks. In parallel, manufacturers are

opening their hitherto proprietary interfaces, leading to

higher flexibility and an improved costs structure.

The single-cable solution is another trend in the

electrical drive technology. It allows further cost savings

and at the same time simplifies the drive system, thus also

offering benefits to the user.

New motor feedback systems family

Kübler [1] is now reacting to these trends with a new

motor feedback systems family : it was developed in close

cooperative partnership with well-known servomotor

(Picture 2) and converter manufacturers. It is based on a

specific platform that offers various possibilities and

advantages for servomotors.

The particular feature of the new Sendix S36 Motor-

Line encoders (Picture 1) is their compact size of only

36.5 mm for a maximum resolution of 2048 pulses per

revolution or 24 bits fully digital. One single size allows

realizing several power ranges which, until now, required

at least two different encoder sizes of for example 36 mm

and 58 mm. The mechanical connection between motor

and encoder is independent of the required performance

range. Previous motors using a 58 mm-size encoder can

now be designed in a more compact way using the Sendix

S36 Motor-Line.

A tapered or a blind hollow shaft and various torque

stops are available for standardization. This ensures the

drive manufacturer more flexibility when selecting the

02 Kübler motor feedback systems for servomotors are space-saving and reliable

mechanical connection. The choice is also broader in

terms of functional safety. According to his choice for a

tapered or for a blind hollow shaft, the drive manufacturer

can select freely his preferred mechanical connection for

his safety concept.

Thanks to the platform concept, the Sendix-S36-Motor-

Line encoders can offer the following interfaces: RS-485 +

sin/cos, Biss, Biss Safety, Biss Line (single-cable solution)

and "SCS open Link" (single-cable solution). Thanks to

this wide choice of interfaces, the electrical interface is no

longer the limiting factor.

Servomotors are also used in applications where they

are subjected to high requirements in terms of shocks and

vibrations. This also results in high requirements for the

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Open-source motor feedback interfaces: the community goes on growing

The sensor and encoder manufacturers Baumer, Hengstler and Kübler presented at the Motek fair in

Stuttgart the open-source standardized interface "SCS open link" for the first time to the public. This

new interface allows the high-performance exchange of bidirectional data between motor and drive, for

example encoder position data.

The three market players see themselves as the initiators of

a growing community that supports the establishment of an

open-source interface standard. The goal is to ensure in the

future higher flexibility to the drive manufacturers when

choosing the suitable encoder for their application. A neutral

certification body will guarantee the compatibility of the

devices from different manufacturers.

"We feel in the servo drives market a strong demand for

compatible motor feedback systems, more flexibility and a

future-proof, non-proprietary standard. Summarized, there is

an urgent desire for an open, safe single-cable solution. We

meet these requirements with the new "SCS open link"

interface. In addition, we durably meet the market trends

relating to increasing performance and functional safety"

said Gebhard F. Kübler, Managing Director of the Kübler

Group at a press conference during the Motek fair on

October 10 in Stuttgart.

"SCS" means Single Cable Solution. "A high-performance

single-cable solution realized with two wires" describes G.

Kübler, who continues: "open means a non-proprietary,

open-source interface that promises to become a proven

certified standard. And 'link' emphasizes the meaning as a

motion protocol for the connection between a rotary or linear

motor feedback encoder and the drive controller." Moreover,

the high significance of safety has been documented by the

suitability of this interface for applications up to SIL3/PLe. To

illustrate the future-proofness of this new solution, he

mentioned the possibilities of condition monitoring and of the

connection of further secondary sensors. IIoT scenarios can

therefore be realized already today. This new interface also

stands out by a transparent license model that ensures the

openness also towards further providers.

Jochen Feiler, Manager of Hengstler GmbH, presented

the technical particularities of "SCS open link" and the

corresponding customer benefits. He first answered the

question: How open is open?

"Focus has actually been set on a future-proof and clear

regulation of the rights of use and on the fact that the three

founder members are basically favorable to the extension of

the sensor manufacturers circle.“ But it is obvious too that

the community has been launched from the customer's

perspective.

"The marked clearly indicated us that an additional closed

interface is not desired“, said J. Feiler. Besides, he

emphasized the advantages of "SCS open link" for drive and

machinery manufacturers: "The high flexibility thanks to

offers from different encoder manufacturers and the easy

implementation of 'SCS open link' based on a micro

controller, which ensures high innovative drive both on

machine and on motor level, are a central feature". J. Feiler

also recalls that the new interface is based on the Acuro link

interface developed by Hengstler and is entirely backward

compatible with it.

Jochen Feller (Hengstler), Gebhard F. Kübler (Kübler) and

Karsten Just (Baumer) present the new motor feedback

interface "SCS open link" (from left to right)

Karsten Just, Sales and Marketing Manager of Baumer

Group, also emphasized: "The union of three renowned

encoder manufacturers is an absolute novelty, which sets

the focus on the meaning of the term community. All relevant

information about this interface is available on a common

web site (www.scs-open-link.org). This web site is the contact

point for interested users as well as for further potential

licensees. The offer of 'SCS open link'-capable sensors and

the market development are driven ahead by every single

member. Therefore, all three founder members will present

individual products and solution approaches at the coming

SPS IPC Drives fair in Nuremberg." K. Just announced

following the press conference a small in-house exhibition.

Many connector and cable manufacturers already belonging

to the "SCS open link" community network presented

themselves there: the companies Helukabel, Igus, Lapp,

Phoenix Contact, SAB Bröckskes, TecniKabel und TE

Connectivity.

03 The single-cable solution for servomotors with the new motor feedback systems by Kübler

encoder connectors. With Safety-Lock, Kübler offers an

optimal answer to this demand. Encoders with Safety-

Lock have interlocked and positively blocked bearings

and a special assembly technique. They withstand

installation errors and shaft loads due for example to

temperature expansion or vibrations.

New single-cable solution

Cables and connectors belong to the main cost drivers in

every automation architecture. A single-cable solution

allows saving material costs, installation work and, last

but not least, space (Picture 3). This solution allows

realizing both voltage supply and data transmission

though one single cable. This is decisive above all for

servomotors in the 40 mm-size.

The tight mounting space in servomotors requires

generally compact sensors and optimized connection

possibilities for the assembly. With "SCS open link",

Kübler now offers a new single-cable solution. It supports

2 and 4-wire applications and allows cable lengths

reaching 100 m, transmission rates up to 10 MBaud and

controller cycles up to 32 KHz. The protocol is certified

up to SIL3 and category 3 for functional safety. A neutral

certification body ensures the compatibility of the devices

from different manufacturers.

But not only the reduction of the costs related to the

connector, the cable and the integration makes the single-

cable solution so interesting. Space for routing cables is

often limited in the applications. The advantages are thus

obvious: Simplification of the connection technology and

less components.

Smart Motor

Besides the usual information such as position and speed,

the new motor feedback systems provide additional

information. They will in the future provide also functions

such as the electronic data sheet (EDS), saving customer-

specific user data and condition monitoring for monitoring

machine condition.

Moreover, connecting additional sensors such as e.g.

temperature sensors used for measuring the winding

temperature is possible. The sensor data is transmitted to

the servo inverter via the fully digital protocol of the

single-cable technology. According to Kübler, the Sendix

S36 Motor-Line encoders with single-cable solution are

ideally equipped for the requirements of IIoT and of the

smart motor. (ih)

Literature

[1] Kübler-Group, Villingen-Schwenningen: www.kuebler.com

Author

Michael Scalet is Global Industry Manager Drive

and Elevator Technology at Kübler Group.

michael.scalet@kuebler.com

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