Selecting an OMRON PLC

This week's blog is on selecting the right family of OMRON PLC for your application. I really want to emphasize that these are general guidelines and that each application may require further evaluation with a specialist.

I had the fortune of spending some time a few weeks ago with Dale Harris from Cross Automation. Dale has had years of experience in specifying, programming, and commissioning OMRON PLCs. He shared with us some key factors in determining which OMRON PLC family to use for a specific application. This is great information to narrow down the extensive offering that OMRON provides.

Through each of these major factors, we'll ask some of the keys questions that need to be answered to get to the proper solution for your industrial application.

OMRON PLC Motion Control

OMRON Sysmac by Cross Company

One of the first major factors you should look at is if your application requires motion control.

  • Does your automation application require closed loop motion control?

If so, you should be looking to the OMRON CJ Series or NJ Series of PLCs.

If not, you may be able to get away with the OMRON CP Series. The CP1H provides pulse outputs for up to 4-axis open loop motion control.

  • How many axes of motion control do you need?

If you need more than 4-axis motion control, you should be looking at the NJ Series of PLCs.


OMRON PLCs by I/O Count by Cross Company

The next major factor is the number of inputs and outputs are required for your application.

  • How many total Inputs and outputs for your application?

If your application requires less than 40 I/O points, you should start by looking at the CP Series.

For applications with more than 100 I/O points, the CJ Series has more capabilities and value.

  • How many Analog Inputs are required?

For an application with 2 or less analog inputs required, the OMRON CP Series can probably do the job.

If you require more than 8 analog inputs, you should be looking into the CJ Series.

  • Do your analog inputs require high resolution?

If your application requires an analog input with resolution greater than 1/6,000, then look to the CJ Series for your solution.

OMRON PLC Communications

OMRON Communications PLCs by Cross Company


What type of communications you are using may be a key consideration for choosing the right PLC.

  • Does your application require Ethernet Communication?

It is more cost effective to have the ethernet functionality built-in to the base unit of the PLC.

For CP Series, the best options are in the CP1L-E Series of PLCs.

For the CJ Series, either look at the CJ2M-CPU31 through CJ2M-CPU35 or the CJ2H-CPU64-EIP through CJ2H-CPU68-EIP.

  • What protocol?

If you are using Modbus TCP / IP, there should not be any issues.

However, if you are Using EthernetIP, we would need a copy of your EDS files to ensure that there will be proper communication between the modules.

If you are using other communications or protocols than what was already mentioned, additional protocol conversion may be needed for your application.

  • Are you are using multiple network ports?

If so, you should look at the CJ Series of PLC.

  • Are serial communications for multiple devices required?

This can also be a limitation of the OMRON CP Series. The CJ Series may be the better solution.

Connected Devices

OMRON Connected Devices by Cross Company


  • What type of devices are you connecting to your PLC?

If there is an Integrated Vision System, the NJ Series is the better solution.

If multiple Bar Code Scanners be connected to your PLC, the OMRON CJ Series will be the right choice.

  • Do you plan on having multiple PLCs?

If your application will require multiple PLCs to communicate with each other, the OMRON CJ Series will be the better choice.


If you answered some of the questions above and have determined that you need to investigate the OMRON CP Series further, you need to look at what OMRON refers to as their "Compact PLC Series". The CP Series is divided into three different types. the chart below shows the key features of the three types:


OMRON CP Series Specs by Cross Company


CP1E Series

OMRON CP1E by Cross Company


The CP1E Series has all the functionality you need to control relatively simple applications, including outstanding positioning capability. You can use the following charts to select the individual model to meet your requirements:




CP1L Series

OMRON CP1L by Cross Company

The CP1L Series is the next level of CP Series PLC. The CP1L offers the compactness of a micro-PLC with the capabilities of a modular PLC. The following chart can help you determine which model suits your needs best:




CP1H Series

OMRON CP1H by Cross Company

The CP1H is the advanced high-speed all-in-one compact PLC. The following chart list the available models and their key features:



OMRON CJ2HEIP by Cross Company

If you answered some of the questions above and have determined that you need to investigate the OMRON CJ Series further, look for the OMRON  "Modular PLC Series". The three types of PLCs in this series:

  • CJ2M Series is ideal for packaging and general machine automation needs.
  • CJ2H Series is ideal for advanced machine automation needs, such as those required in image processing inspection of electrical components and high speed sorting on conveyors.
  • CJ1G-P Series is an engine for process variables. It has built-in Integrated Loop Control and Sequence Control.

You can refer to the following chart for the CJ Series Models and their key characteristics:

OMRON CJ Series specs

If you have any specific questions on this topic, please feel free to give me a call or email me!


Contact Cross Company

Ryan is a Certified Fluid Power Pneumatic Specialist (CFPPS) with Cross Company Motion Solutions.