1. Encoders – Basic Training
Mandee Liberty & Vikram Phadke
National Encoder Product Specialists

2. Typical Industrial System
Input
Output
Operation
(Application)
Controller
Feedback
Sensor
Other components – HMI, Mechanical, etc
Input
I/O Types
Discrete
Analog
Communication
Encoders 2

3. Encoders within a Control System
Feedback
Sensor

4. What is an encoder? Encoder Definitions
An encoder is a device which converts a mechanical information of a shaft or position into an electrical signal
Encoder

5. How is this accomplished?
Encoder Definitions
How is this accomplished?
As the code disc rotates, it shutters light from the LED and is received and transmitted as square\sine waveforms
Receiver / Sensor
Code disc
Lens
Transmitter / LED
Shaft

6. Encoder Selection Process
Mechanical Considerations
Electrical Interface
Type (Rotary, Linear, Incremental, Absolute)
Give everyone a selection guide: Explain the Selection Guide

7. Encoder Selection Process
Type (Rotary, Linear, Incremental, Absolute)
Give everyone a selection guide: Explain the Selection Guide

8. Types of Encoders
Encoder
Rotary Encoder
Linear Encoder

9. Types of Encoders Rotary Linear
Convert Angular Position into Analog or Digital Signal
Encoders for rotary motion and measuring angle, speed or velocity
Linear
Convert Linear distance movement to Analog or Digital Signal
Encoders for measuring distance travelled, positioning, location information.

10. Types of Encoders
Encoder
Linear Encoder
Wire Draw
Linear with Scale

11. Types of Encoders Wiredraw
Convert pulled wire length distance to feedback
Absolute and Incremental
Analog, digital or Bus feedback interfaces
Distance: up to 50m
With Scale
Two part devices; Active Head, Passive Scale
Absolute Positioning
Scale : Magnetic Tape or Elements
Hiperface, SSI, Bus Interfaces
Distance: up to 1700m

12. Types of Encoders Encoder Rotary Encoder Linear Encoder Incremental
Absolute
Wire Draw
Linear with Scale
Incremental
Absolute

13. Incremental Encoders Incremental
Produces electrical pulses or increments with linear or rotary motion
Signals can be square or sinusoidal waves
Signals start over at power up, or after a power failure. In other words, an incremental encoder does not retain position after a power cycle
Incremental encoders are typically used for speed or applications that do not require absolute position

14. Code disc for absolute encoders
Provides a unique value for every shaft or linear position
Absolute encoders retain their position after a power cycle
Signals typically use SSI, parallel, or field bus interfaces (Ethernet/IP, EtherCAT, Profinet, Devicenet, CANopen, Profibus, etc)
Absolute encoders are used in applications were position information is necessary
Code disc for absolute encoders
LED
Lens
Scanning mask
Code disc
Photo-
Elements

15. Encoder Selection Process
Type (Rotary, Linear, Incremental, Absolute)
Electrical Interface

16. Types of Encoders
Encoder
Rotary Encoder
Incremental
Absolute

17. Incremental Encoders Output Channels
produce electrical pulses or increments (usually as a square wave) with linear or rotary motion of the encoder
Resolution
The number of pulses or increments per channel, per revolution. Also known as Pulses Per Revolution, or PPR
Quadrature:
The standard convention is to output two square wave channels along with their complements
Channels A and B are offset by ¼ of a cycle – using all four channels with this output, we can interpolate 4 positions within one pulse cycle. This is known as “quadrature”
The 1/4th offset also allows us to see which direction the encoder is turning based on what channel is leading. If channel A goes high first followed by channel B, we can determine the direction of rotation, and visa versa.
: Name (Date)

18. Incremental Encoders Electrical Signals
Output Voltages
Standard output voltages are HTL, TTL or Open Collector. These refer to the amplitude of the square waves
HTL (High Threshold Logic)
Also known as “push pull”
The output voltage will be the same as the supply voltage (e.g if the supply on the encoder is 24V, the output signal will also be ~24V)
TTL (Transistor Transistor Logic)
Also known as a “differential line driver” or “RS422”
The output voltage will always be 5V regardless of the supply voltage on the encoder
Open Collector
Instead of outputting a signal of a specific voltage or current, the output signal is applied to the base of an internal NPN transistor whose collector is externalized
: Name (Date)

19. Incremental Encoders Interface Summary
Incremental Encoder – Electronic Interface Summary
Standard Supply voltages are 5VDC, VDC, and 8-24VDC
Standard outputs are TTL, HTL and Open collector
Incremental
Electronic Interface
TTL / RS 422
Supply = 5V
TTL / RS 422
Supply = V
HTL / Push Pull
Supply = V
Open Collector
Supply = 8-24 V

20. Absolute Encoders Singleturn vs Multiturn Absolute Encoders
Rotary Encoder
Incremental
Absolute
Singleturn
Multiturn

21. Singleturn and Multiturn Absolute
Measures the Absolute position within 1 revolution/turn
Multiturn
In Addition, measures the number of revolutions as well.

22. Absolute Encoder Interfaces
Electronic Interface
Parallel
SSI
BUS
Absolute encoders transmit position information via serial, parallel bits or via bus communication.
Parallel wires can provide position information as one bit per wire. Parallel bit communication has distance restrictions – usually 10 M. Electric noise interference and power supply capabilities are limiting factors.
BUS communication is very efficient, but also has distance limitations – usually 100 M per drop.
Serial communication can run the longest distances – sometimes in excess of 1000 M. SSI (Synchronous Serial Interface) is a popular format for serial communication.

23. Parallel Output Parallel Output Connection Benefits Drawbacks
First form of communication for absolute encoders
Connection
Point-to-point communication where each output wire represents a different data bit
Benefits
Direct output to digital inputs
Fast (60us typically)
Drawbacks
Complex cabling due to separate bit wires
High cost
: Name (Date)

24. Synchronous Serial Interface (SSI)
Very common serial interface standard for industrial applications
Developed by Stegmann in 1984 for absolute encoders – now in many products
Connection
Point-to-point connection from a master (PLC, microcontroller) to a slave (encoder)
Benefits
Simple cabling, especially compared to parallel outputs
Fast communication speeds
Low cost
Drawbacks
Point-to-point connection, topology restrictions
: Name (Date)

25. Network Encoders
What do we (or the customer) mean when we say “network encoder”?
A network is a collection of products (sensors, HMIs, processes, etc) that are connected to a central controller or share information between parts.
Also known as Field Bus
Example: an Internet VPN (virtual private network):
: Name (Date)

26. Field Bus Interfaces Field Bus Benefits Disadvantages
Industrial network system that connects multiple products in a manufacturing plant or on a machine
Benefits
Products are no longer point-to-point which allow multiple products to be connected to one controller
Generally does not require as many cables as a point to point configuration, and cables do not need to be as long. This saves on system costs.
Typically the controller has more flexibility for configuration and information gathering
Disadvantages
The network topologies are generally more complex
Individual components cost more than standalone products (potential system savings, however)
: Name (Date)

27. SICK Absolute Encoder Fieldbus Interfaces
AFx60 Series
ATM60 Series
NEW!
: Name (Date)

28. Electrical Interface Summary Things to know when choosing an encoder
Incremental Encoders
Resolution (PPR)
Supply Voltage
Output Voltage (HTL, TTL or Open Collector)
Programmable Encoders:
DFS60 and DFS2x encoders let you program ALL electrical configurations except an open collector output
Absolute Encoders
Resolution (singleturn, multiturn)
Output type
Parallel (output voltage needed)
SSI
Fieldbus
Programmable Encoders
Programmable options for SSI encoders to program the resolution. All field bus encoders are programmable over their respective networks
: Name (Date)

29. Encoder Selection Process
Type (Rotary, Linear, Incremental, Absolute)
Electrical Interface
Mechanical Considerations

30. Mechanical Characteristics
Housings and Connection
Housing Size
Cable or Connector
Shafts
Solid, blind hollow, through hollow
Sizes, shaft load
Flange
Face mounting flange
Servo flange
Square Flange
Tethers

31. Encoder Selection Process
Type (Rotary, Linear, Incremental, Absolute)
Electrical Interface
Mechanical Considerations

32. Absolute Singleturn Encoders Absolute Multiturn Encoders
Product Overview - Rotary Encoders
Absolute Singleturn Encoders
Absolute Multiturn Encoders

33. Product Overview - Linear Encoders

34. Key Products in 2013 Choice encoders that will solve most applications
DFS60 with PGT-10-S Programming Tool
DFS20/25 Incremental Encoder
AFx60 Series With Ethernet
BCG Wiredraw with Analog Output
Handheld, battery operated programming tool
Easy menu structure for fast setup and flexibility
Can be used for diagnostics with the display or as a cloning module
USA sized encoders with SICK’s “F”-Technology:
Wide set bearings for even shaft loading
Metal code disc for high vibration and temperature
Programmable using the PC-based tool
Absolute single- and multi-turn encoders with EtherNet/IP, EtherCAT, and Profinet interfaces
Device Level Ring (DLR) functionality with the EtherNet/IP version
Superior diagnostics for temperature, speed, runtime, and many more
Compact wiredraw encoder for applications in tight spaces
Up to 10m of measuring length
Analog output scalable directly on the encoder for fast commissioning

35. Fields of applications
Packaging
Print & Paper
Wood industry
Machine Tooling
Automotive
Ports & Cranes
Handling
… And many more

36. Application Examples
OVERHEAD CRANE– AFM60 EtherNet/IP used to track position of crane
CONVEYORS – DKV60 used to track speed of conveyor

37. BOTTLING – Absolute encoder AFS60 to track position of fillers
Application Examples
WIND TURBINE – Absolute encoder AFM60 for gandala and blade angle tracking
BOTTLING – Absolute encoder AFS60 to track position of fillers

38. STADIUM ROOF – Position with KH53 Linear Encoder
Application Examples
STADIUM ROOF – Position with KH53 Linear Encoder
LIFT APPLICATIONS – Height and Width positioning using BGC Wiredraw Encoders

39. Demonstration Videos & Application Animations
Additional Resources
SICK University Tour March – May 2013
Tech Tuesdays Check for schedule
Product Training
Demo Cases
Demonstration Videos & Application Animations

40. Encoder Selection Guide
Marketing Tools
Encoder Catalog
*Update in 2013
Encoder Selection Guide
Application Book

41. Thank you for your attention.