The Do-more PLCs perform EtherNet/IP with Unconnected Explicit Messaging.

Once the CLICK EtherNet/IP Adapter setup is completed and Data Blocks have been created, the EIPMSG instruction in Do-more is used to read and write data.

In this example, we have created a data block of 100 registers for the Input data and 100 registers for the Output data as shown below in the CLICK software. Take note of the Class, Instance, Attribute and Size of each Data Block configuration.

Below is the ladder logic example of the EIPMSG instruction being used to read and write data via EtherNet/IP.

 

Details for using the EIPMSG instruction for reading (GET) and writing (SET) data are shown below. The EIPMSG instruction can be configured to send at a Continuous Interval or to be sent once on the Leading Edge of the Enable input.

For reading (GET), it is advisable to use the Continuous Interval option but for writing (SET), data should only be sent when the values change in the Do-more PLC. It wastes bandwidth to write the same values over and over, and it can also needlessly overwrite other PLC data being sent from a different EtherNet/IP scanner/client PLC.

In each instruction:

1. Use the EtherNet/IP Device. In this example we are using the built-in client, @IntEIPClient.
2. Enter the IP Address of the CLICK PLC being targeted.
3. Enter the Class, Instance and Attribute shown in the CLICK EtherNet/IP Adapter setup for the particular connection and operation.
4. Select the Service.

1. For Reading data select Get Attribute (14, 0x0E).
2. For Writing data select Set Attribute (16, 0x10).

5. Make sure Max Length in BYTES is set to match the size of the Data Blocks created earlier. In this example, that is 200 bytes.
6. Fill out the other fields to fit your application.

 

EIPMSG as a Read Instruction

EIPMSG as a Write Instruction

 

When the Do-more EIPMSG read instruction is enabled, all the values in the Input block of the CLICK PLC should be visible:

 

CLICK Data View

 

Do-more Data View

 

When the Do-more EIPMSG write instruction is enabled, all the values in the Output block of the Do-more should be written to the Output block of the CLICK PLC:

 

CLICK Data View

Related Topics:

EtherNet/IP Overview

EtherNet/IP Adapter Setup

Communications Ethernet

CLICK Example for AB CompactLogix

CLICK Example for Productivity Series PLC
General & Extended Status EtherNet IP Error Codes