PLC Program for Omron Encoder Interfacing with Omron PLC

In the Previous Post we saw that how can we connect encoder with PLC for the feedback and calculation of speed and position. In this section we will clearly discuss the PLC Programming of Encoder and associated settings in CX Programmer. If you are unfamiliar with encoder connection with PLC then you can review here. Also you can see the basics of Encoder and some information on types of encoder here.

Settings In CX-Programmer to configure High speed Input:-

First of all we have to configure the high speed counter inputs to which we are connecting encoder outputs. we will see here step by step detail as how to configure it. We are taking example of Omron PLC Cp1E here, however similar settings are there for omron PLC CP1H.

Just open CX-Programmer, then click on settings and go to rightmost tab i.e Built in Input. Under this tab you select Linear and Reset of encoder accordingly. You can see the below picture for a better understanding.


Note:- Click on the picture for a better enlarged View.


Reset of Pulses of Encoder can be done through Z phase or Either Software Reset i.e through our PLC Program. In the Input setting we can choose either of differential type or Up-down input, generally these are selected if we want to track both forward and reverse position i.e while calculating the position of job-piece. In these cases if encoder shaft moves in forward direction and we read 300 pulses and encoder shaft rotate in reverse direction then the pulses will decrease accordingly.

Recommended Article: Using High Speed Counter in Omron PLC

If in any application you just want that pulses from encoder should increase despite of its rotation direction then select Pulse + or Increment as input type in the settings section. Now we are done with settings part.

PLC Program for Reading Encoder Pulses :-

Now we will see how to do the PLC Programming for reading the PV values of encoder. Well there is one instruction PRV in omron PLC which is used to read the high speed counter input values, we have to write that instruction accordingly. In the PRV Instruction we have to specify the Port i.e at which Port we are connecting the encoder, #0010 for port 1, #0011 for port 2, #0012 for port 3 and so on , also we have to specify in the control word as #0 i.e we are reading the value. Also we can reset the encoder PV by setting the System bit, all the things are clearly depicted in PLC Program. You can download sample PLC program for Omron Encoder interfacing here.

If you are facing any kind of problem regarding PLC Programming with encoders yo can write in comment section and we will get back to you. You can subscribe to Automation-Talk by Email for more such tutorials.

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