Mandee Liberty & Vikram Phadke
National Encoder Product Specialists
: Encoders – Basic Training
: SICK, Inc. : Confidential
Typical Industrial System
Input Output
Feedback
Controller Operation
(Application)
Sensor
2
: SICK, Inc. : Confidential
Encoders within a Control System
3
FeedbackSensor
: SICK, Inc. : Confidential
What is an encoder?: An encoder is a device which converts a mechanical information of a shaft or
position into an electrical signal
Encoder
Encoder Definitions
4
: SICK, Inc. : Confidential
Encoder Definitions
5
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
: SICK, Inc. : Confidential 6
Encoder Selection Process
: SICK, Inc. : Confidential 7
Encoder Selection Process
: SICK, Inc. : Confidential
Encoder
Rotary Encoder Linear Encoder
Types of Encoders
8
: SICK, Inc. : Confidential 9
Types of Encoders
: SICK, Inc. : Confidential
Encoder
Linear Encoder
Wire Draw Linear with Scale
Types of Encoders
10
: SICK, Inc. : Confidential 11
Types of Encoders
: SICK, Inc. : Confidential
Encoder
Rotary Encoder
Incremental Absolute
Linear Encoder
Wire Draw Linear with Scale
AbsoluteIncremental
Types of Encoders
12
: SICK, Inc. : Confidential 13
Incremental
Produces electrical pulses or incrementswith 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 incrementalencoder does not retain position after apower cycle
Incremental encoders are typically used forspeed or applications that do not require absolute position
Incremental Encoders
: SICK, Inc. : Confidential
Absolute Encoders
14
Absolute
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 businterfaces (Ethernet/IP, EtherCAT, Profinet,
Devicenet, CANopen, Profibus, etc)
Absolute encoders are used in applications were position information is necessary
Code disc for absoluteencoders
LEDLens
Scanning mask
Code disc Photo-
Elements
: SICK, Inc. : Confidential
Encoder Selection Process
15
Electrical Interface
: SICK, Inc. : Confidential
Encoder
Rotary Encoder
Incremental Absolute
Types of Encoders
16
: SICK, Inc. : Confidential
Incremental EncodersOutput Channels
: Incremental encoders - 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) 17
: SICK, Inc. : Confidential
Incremental EncodersElectrical 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 supplyvoltage (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 ofthe 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) 18
: SICK, Inc. : Confidential 19
Incremental Encoder – Electronic Interface Summary
•Standard Supply voltages are 5VDC, 10-32 VDC, and 8-24VDC•Standard outputs are TTL, HTL and Open collector
Incremental
Electronic Interface
TTL / RS 422
Supply = 5VTTL / RS 422
Supply = 10 ... 32V
HTL / Push Pull
Supply = 10 ... 32V
Open Collector
Supply = 8-24 V
Incremental EncodersInterface Summary
: SICK, Inc. : Confidential
Encoder
Rotary Encoder
Incremental Absolute
MultiturnSingleturn
Absolute EncodersSingleturn vs Multiturn Absolute Encoders
20
: SICK, Inc. : Confidential 21
Singleturn and Multiturn Absolute
: SICK, Inc. : Confidential
Absolute
Electronic Interface
SSIParallel BUS
22
Absolute Encoder Interfaces
: SICK, Inc. : Confidential
: Parallel Output- 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)
: Name (Date) 23
: Drawbacks- Complex cabling due to separate bit wires
- High cost
Parallel Output
: SICK, Inc. : Confidential
: 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
: Name (Date) 24
: Drawbacks- Point-to-point connection, topology restrictions
Synchronous Serial Interface (SSI)
: SICK, Inc. : Confidential
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 (virtualprivate network):
: Name (Date) 25
: SICK, Inc. : Confidential
: Field Bus- 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) 26
Field Bus Interfaces
: SICK, Inc. : Confidential
SICK Absolute Encoder Fieldbus Interfaces
: Name (Date) 27
ATM60 SeriesAFx60 Series
: SICK, Inc. : Confidential
Electrical Interface SummaryThings 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) 28
: SICK, Inc. : Confidential
Encoder Selection Process
29
Mechanical Considerations
: SICK, Inc. : Confidential 30
: 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
Mechanical Characteristics
: SICK, Inc. : Confidential
Encoder Selection Process
31
: SICK, Inc. : Confidential
Product Overview - Rotary Encoders
Absolute Singleturn Encoders Absolute Multiturn Encoders
32
: SICK, Inc. : Confidential
Product Overview - Linear Encoders
33
: SICK, Inc. : Confidential
Key Products in 2013Choice encoders that will solve most applications
34
AFx60 SeriesWith Ethernet
DFS60 with PGT-10-SProgramming Tool
BCG Wiredrawwith Analog Output
DFS20/25Incremental Encoder
• 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
: SICK, Inc. : Confidential
Handling
Wood industry
Automotive Ports & Cranes
Packaging
Machine Tooling
Print & Paper
… And many more
Fields of applications
35
: SICK, Inc. : Confidential
Application Examples
36
OVERHEAD CRANE– AFM60 EtherNet/IP used to track position of crane
CONVEYORS – DKV60 used to track speed of conveyor
: SICK, Inc. : Confidential
Application Examples
37
WIND TURBINE – Absolute encoder AFM60 for gandala and blade angle tracking
BOTTLING – Absolute encoder AFS60 to track position of fillers
: SICK, Inc. : Confidential
Application Examples
38
STADIUM ROOF – Position with KH53 Linear Encoder
LIFT APPLICATIONS – Height and Width positioning using BGC Wiredraw Encoders
: SICK, Inc. : Confidential
Additional Resources
39
Demonstration Videos & Application Animations
SICK University TourMarch – May 2013
Product Training Demo Cases
Tech Tuesdays Check www.sickusa.com for schedule
: SICK, Inc. : Confidential
Marketing Tools
40
Encoder Selection Guide
Application BookEncoder Catalog*Update in 2013
: Thank you for your attention.