Introduction

IO-Link is the first standardized IO technology worldwide (IEC 61131-9) for communication with devices such as pressure sensors, electric actuators, RFID readers, light stacks, temperature sensors and many others.

The powerful point-to-point communication is based on the long-established 3-wire devices connection without additional requirements regarding the cable material. So, IO-Link is no fieldbus but the further development of the existing, tried-and-tested connection technology for devices. Source: (www.io-link.com)

Festo’s CPX automation platform and CTEU-EP communication node have the ability to add IO-Link devices (from Festo and/or third parties). Therefore, additional products can be added because IO-Link is fieldbus independent and can be integrated into all fieldbus systems. (This technical write-up will only discuss Ethernet/IP fieldbus).

These features, for supporting IO-Link, are only roughly documented in the standard manuals. This write-up is intended to support these additional features, specifically including how to set and read IO-Link Parameters.

• Download EDS files
• How to install EDS files?
• Configuration of the CPX-E-EP with Festo Automation Suite
  • Setting basic parameters to CPX-E-EP

• Addressing concept
• Working with Device Web Page
• Adding the CPX-E-EP system in Studio5000
• Controller tags
• IO-Link Integration with Ethernet/IP
• Read parameters on an IO-Link device
• Write parameters to an IO-Link device

Download EDS files

1. Visit www.festo.com and type the product code (e.g., CPX-E-EP) in the search field.

2. Go to “Download”.

3. Click on “Software”.

4. Download desired file (e.g., Ethernet/IP EDS).

Process Data Out

So, in the most basic operation of this IO-Link Device, we can activate outputs or Process Data Out to execute movements. For example, if we activate bit 0 of the Process Data Out, the actuator will move to the “In” position and will send as feedback bit 3 (State “Device”) and bit 2 (State “Move”) of the Process Data In while it is moving. When it reaches the position it will send bit 0 State “In” and turn off the bit 2 (State “Move”). Something that makes the IO-Link protocol very useful is the ability to read or write parameters to the device. In the following sections you will learn how to read or write parameters to an IO-Link device.

IO-Link Integration with Ethernet/IP

As described above, the behavior of the CPX-E system can be parametrized with Festo software or using a high-order controller. Here, a distinction is made between the following variants:

• System parameters
• Module parameters (module-specific and channel-specific)
• Parametrization of the diagnostic memory

You can find a detailed description of the individual parameters in the corresponding module user manual / product description.

The following section is an excerpt from the “Description / Function of the CPX-E-EP bus module manual” available on the Festo webpage. This is a representation of the CPX-E system within the Ethernet/IP object model.

The CPX-E system supports various services depending on the object:

6. For this group of options, consider:

• Source Element: For this part, we create an array variable type INT [2]. The first part of this array “Read_Param_Ch1_Source_Element [0]” refers to the Index of the parameter to be read. The second part of the array “Read_Param_Ch1_Source_Element [1]” refers to the Subindex of the parameter to read. Hint: In the Source Element section, you must select the root of the array variable (i.e., Read_Param_Ch1_Source_Element).
• Source Length: 3 (bytes), source length is always “3” for read access.
• Destination Element: This part follows the formula Tag of SINT[1+n]. For example, the parameter that we are going to read on our IO-Link device (Intermediate Position) has a length of 4 bytes, therefore, the destination variable will be an array type SINT[5] (i.e., Read_Param_Ch1_Destination_Element). This variable contains in the first byte [0] the status / error code of the request, and from [1] you will find the value of the parameter to read.

7. Click on “Apply” then click on “OK”.

Disclaimer

This post is provided solely for the purpose of offering setup assistance and general guidance. It is important to note that the ultimate responsibility for ensuring the overall safety and proper functionality of the machine lies with the System Integrator / End User. It is crucial to exercise caution, adhere to proper safety protocols, and consult relevant experts or professionals when necessary.

Although Festo employees will be contributing to this blog, please note this is not the official Festo support channel. For more timely technical support please reach out to your regional Festo support channel and/or consult user manuals and relevant documentation.