Jan 28, 2015

How to Connect Omron Rotary Encoder to PLC

How to Connect Omron Rotary Encoder to PLC
Encoders finds their application in various applications in industry. From Instrumentation point of view we can see Encoder as a device which provide us the pulses for rotatory movement.In Most of the applications it is used to provide the feedback and thus a better controlling.

Omron Rotary encoder E6B2 comes with open collector output and as well as line driver output. It has external shaft dia up to 40mm and it has a resolution of up to 2000PPR.

Some may want to know what is PPR in encoders ?? well PPR stands for Pulse Per Revolution i.e the number of pulses it will be giving in one full revolution.Also as per our need we can select either PNP or NPN type output. Generally in all the cases we need to interface the encoder with PLC to receive the PULSES.

The use of encoders in Automation is for detecting/calculating the length or distance traveled with the input from encoder pulses , for measuring the speed or for high-processing of data. For more detail on encoders you can see here.

How to Connect Encoder to PLC?

For connecting the Encoder to our PLC we have to make sure that our PLC accepts high speed counter inputs and we have to connect the encoder accordingly to that terminals only. Omron PLC CP1E/CP1H have 4 high speed counter inputs and we can connect up to 4/6 encoders.
Omron encoder E6B2 series have 5 wires and of different colour. Make connections as depicted below.

Wire Colour -------------------------------------------------------------Type

Brown------------------------------------------------------------------- + 24 V DC
Blue ------------------------------------------------------------------- 0 V Dc
Black ------------------------------------------------------------------ Output Phase A
White ------------------------------------------------------------------ Ouput Phase B
Orange ----------------------------------------------------------------- Phase Z

So connect your Encoder accordingly as shown above. Here we will tell you how to interface it with PLC. We will take example of OMRON PLC CP1E. We have to just connect 3 wires to PLC high speed counter Terminals and configure them in the software for Receiving the Pulses.
Interfacing the Encoder with Omron PLC CP1E:-


We will take example here as connecting the encoder to High speed counter 0.


Encoder Side--------------------------------------------------------PLC Side

Black-------------------------------------------------------------- 0.0
White-------------------------------------------------------------- 0.1
Orange------------------------------------------------------------- 0.4

Similarly we can connect it to any high speed counter input , just we have to check what are the terminals assigned for that HIGH Speed Counter in PLC.

After making the connections we have to write the suitable PLC Program for the reading of Pulses and processing the PV value of Encoder.

PLC Programming and necessary settings in CX-Programmer will be discussed in next post. So just reading here and also you can subscribe to get all related updates in yours Inbox. If you are facing any problem in connecting up your encoder then feel free to write in comment sections. PLC Programming for Encoder will be discussed in next post. If you like our articles do Subscribe to Automation-Talk by Email for more such awesome articles.

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  1. thanks for your valuable information how can i access the encoder values to CX program.

  2. Dear Karmegam ,
    You can easily access the encoder values in CX Programmer
    You have to write an instruction PRV for this
    SYntax is as follows:-
    PRV #0 #0 D100
    First data defines port , second the control word and third defines the result word where encoder pulses will be stored.
    If you further help feel free to ask.
    Welcome to my Blog.

  3. Dear sir,

    Im a beginner PLC programmer.So can you teach to me how to programme plc ladder for OMRON CQM1 CPU11 with Encoder 2000pulse input and energize relay output when reach my set point. I think, I need to use high speed counter for this sequence.So can you teach to me how to edit this ladder programme at CX-PROGRAMMER version 2.0.


  4. how to connect line driver encoder to cp1e plc?

  5. How to conect omron 350 ppr to fx series?


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