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Encoders – Basic Training

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Presentation on theme: "Encoders – Basic Training"— Presentation transcript:

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.

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