The three common output types are open-collector (pull), single-ended (push-pull), and differential line drivers (push-pull). The three common types of encoder output drivers corresponding to these devices are: Sinking outputs are typically based on NPN transistors, while sourcing outputs are typically based on PNP transistors. Similarly, a sinking input should be paired with a sourcing output. Sourcing I/O: A sourcing device supplies voltageĪlthough exceptions exist, an ideal circuit matches a sourcing input (e.g., PLC) with a sinking output (e.g., encoder).Sinking I/O: A sinking device provides a path to ground.These analog encoders require output drivers to convert the photodiode output to a square wave signal and send it across to the control/counter.Įlectrical I/O can be classed as sinking or sourcing. A disadvantage is the increased cost of running extra wire. This is done by generating two signals and referencing them to each other instead of ground. The advantage of a differential signal is that it offers greater resistance to electromagnetic interference. Incremental encoders can be connected to the control/counter via single ended (one wire per channel) or differential (two-wires per channel) schemes. Learn more about absolute encoder output types here Incremental Encoder Output This page focuses on incremental encoder output. Ethernet network based protocols (EtherNet/IP, Profinet or EtherCAT are examples).Field bus protocols (CanOpen and DeviceNet are examples).Serial output (point-to-point interfaces such as SSI and BiSS are examples).Differential line driver encoder outputįor absolute encoders there are four major encoder output options:.Encoder Output: How to Specify the Right Output DriverĪn encoder output driver amplifies and processes raw encoder signal into square-wave signals that can be transmitted to the readout device or drive.įor incremental encoders, there are 3 types of encoder output:

Differential output voltage