: Encoders – Basic Training Mandee Liberty & Vikram Phadke National Encoder Product Specialists Typical Industrial System Input Operation (Application) Controller Output Feedback Sensor : SICK, Inc. : Confidential 2 Encoders within a Control System Feedback Sensor : SICK, Inc. : Confidential 3 Encoder Definitions What is an encoder? : An encoder is a device which converts a mechanical information of a shaft or position into an electrical signal Encoder : SICK, Inc. : Confidential 4 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 : SICK, Inc. : Confidential 5 Encoder Selection Process Type (Rotary, Linear, Incremental, Absolute) Electrical Interface Mechanical Considerations : SICK, Inc. : Confidential 6 Encoder Selection Process Type (Rotary, Linear, Incremental, Absolute) : SICK, Inc. : Confidential 7 Types of Encoders Encoder Rotary Encoder : SICK, Inc. Linear Encoder : Confidential 8 Types of Encoders Linear Rotary • Convert Angular Position into Analog or Digital Signal • Convert Linear distance movement to Analog or Digital Signal • Encoders for rotary motion and measuring angle, speed or velocity • Encoders for measuring distance travelled, positioning, location information. : SICK, Inc. : Confidential 9 Types of Encoders Encoder Linear Encoder Wire Draw : SICK, Inc. : Confidential Linear with Scale 10 Types of Encoders Wiredraw With Scale • Convert pulled wire length distance to feedback • Absolute and Incremental • Analog, digital or Bus feedback interfaces • Distance: up to 50m : SICK, Inc. : Confidential • Two part devices; Active Head, Passive Scale • Absolute Positioning • Scale : Magnetic Tape or Elements • Hiperface, SSI, Bus Interfaces • Distance: up to 1700m 11 Types of Encoders Encoder Rotary Encoder Incremental Linear Encoder Absolute Wire Draw Incremental : SICK, Inc. : Confidential Linear with Scale Absolute 12 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 : SICK, Inc. : Confidential 13 Absolute Encoders Absolute Code disc for absolute encoders LED Lens 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 Scanning mask Code disc : SICK, Inc. PhotoElements : Confidential 14 Encoder Selection Process Type (Rotary, Linear, Incremental, Absolute) Electrical Interface : SICK, Inc. : Confidential 15 Types of Encoders Encoder Rotary Encoder Incremental : SICK, Inc. Absolute : Confidential 16 Incremental Encoders Output Channels : Incremental encoders - : Resolution - : produce electrical pulses or increments (usually as a square wave) with linear or rotary motion of the encoder 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. : SICK, Inc. : Confidential : Name (Date) 17 Incremental Encoders Electrical Signals : Output Voltages - : 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) - : Standard output voltages are HTL, TTL or Open Collector. These refer to the amplitude of the square waves 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 : SICK, Inc. : Confidential : Name (Date) 18 Incremental Encoders Interface Summary 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 = 5V : SICK, Inc. TTL / RS 422 Supply = 10 ... 32V : Confidential HTL / Push Pull Supply = 10 ... 32V 19 Open Collector Supply = 8-24 V Absolute Encoders Singleturn vs Multiturn Absolute Encoders Encoder Rotary Encoder Incremental Absolute Singleturn : SICK, Inc. Multiturn : Confidential 20 Singleturn and Multiturn Absolute Multiturn Singleturn • Measures the Absolute position within 1 revolution/turn : SICK, Inc. : Confidential • Measures the Absolute position within 1 revolution/turn • In Addition, measures the number of revolutions as well. 21 Absolute Encoder Interfaces Absolute Electronic Interface Parallel : SICK, Inc. SSI : Confidential BUS 22 Parallel Output : Parallel Output - : Connection - : First form of communication for absolute encoders Point-to-point communication where each output wire represents a different data bit : Benefits - Direct output to digital inputs Fast (60us typically) : SICK, Inc. Drawbacks - : Confidential Complex cabling due to separate bit wires High cost : Name (Date) 23 Synchronous Serial Interface (SSI) : Synchronous Serial Interface (SSI) - : Connection - : Very common serial interface standard for industrial applications Developed by Stegmann in 1984 for absolute encoders – now in many products 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 : SICK, Inc. : Confidential Drawbacks - Point-to-point connection, topology restrictions : Name (Date) 24 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): : SICK, Inc. : Confidential : Name (Date) 25 Field Bus Interfaces : Field Bus - : Benefits - : Industrial network system that connects multiple products in a manufacturing plant or on a machine 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) : SICK, Inc. : Confidential : Name (Date) 26 SICK Absolute Encoder Fieldbus Interfaces AFx60 Series ATM60 Series : SICK, Inc. : Confidential : Name (Date) 27 Electrical Interface Summary Things to know when choosing an encoder : : Incremental Encoders - Resolution (PPR) - Supply Voltage - Output Voltage (HTL, TTL or Open Collector) Absolute Encoders - Resolution (singleturn, multiturn) - Output type ▪ ▪ ▪ - Programmable Encoders: DFS60 and DFS2x encoders let you program ALL electrical configurations except an open collector output : SICK, Inc. : Confidential 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 Encoder Selection Process Type (Rotary, Linear, Incremental, Absolute) Electrical Interface Mechanical Considerations : SICK, Inc. : Confidential 29 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 : SICK, Inc. : Confidential 30 Encoder Selection Process Type (Rotary, Linear, Incremental, Absolute) Electrical Interface Mechanical Considerations : SICK, Inc. : Confidential 31 Product Overview - Rotary Encoders Absolute Singleturn Encoders : SICK, Inc. Absolute Multiturn Encoders : Confidential 32 Product Overview - Linear Encoders : SICK, Inc. : Confidential 33 Key Products in 2013 Choice encoders that will solve most applications DFS60 with PGT-10-S Programming Tool • • • 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 : SICK, Inc. DFS20/25 Incremental Encoder • USA sized encoders with SICK’s “F”-Technology: • Wide set bearings for even shaft loading • • • Absolute single- and multiturn encoders with EtherNet/IP, EtherCAT, and Profinet interfaces • Device Level Ring (DLR) functionality with the EtherNet/IP version Metal code disc for high vibration and temperature Programmable using the PC-based tool : Confidential BCG Wiredraw with Analog Output AFx60 Series With Ethernet • 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 34 Fields of applications Machine Tooling Packaging Print & Paper Wood industry Automotive Ports & Cranes Handling … And many more : SICK, Inc. : Confidential 35 Application Examples OVERHEAD CRANE– AFM60 EtherNet/IP used to track position of crane CONVEYORS – DKV60 used to track speed of conveyor : SICK, Inc. : Confidential 36 Application Examples WIND TURBINE – Absolute encoder AFM60 for gandala and blade angle tracking BOTTLING – Absolute encoder AFS60 to track position of fillers : SICK, Inc. : Confidential 37 Application Examples STADIUM ROOF – Position with KH53 Linear Encoder LIFT APPLICATIONS – Height and Width positioning using BGC Wiredraw Encoders : SICK, Inc. : Confidential 38 Additional Resources SICK University Tour March – May 2013 Tech Tuesdays Check www.sickusa.com for schedule Product Training : SICK, Inc. Demo Cases : Confidential Demonstration Videos & Application Animations 39 Marketing Tools Encoder Catalog Encoder Selection Guide Application Book *Update in 2013 : SICK, Inc. : Confidential 40 : Thank you for your attention.