Ethernet/IP Acyclic communication


I successfully use CompactCom EIP M40 on my project with cyclic communication since years without any issue on various application.

Usually, for debug and testing I use EIPScan software with a Class#1 connection.

Now I need to add to the same project some acyclic communication. This should be possible adding on EIPScan a Class#3 connection.
I use some settings that I found on this forum to send message but I get an error as soon as I start connection.

Some of this setting are not so clear for me I just copied it from another user. (such as service and class)
Inside my application, when I start connection for class #3 object I’ve no any action or event triggered apparently. I don’t know If I miss some setting in HMS driver for acyclic com.

Someone have experience in this type on connection and can suggest me some document or example to activate this and checking with EIpscan ??

Thank you

Hi Mutty,
A class 3 connection is an explicit request. The service is the type of request being made, this relates to the CIP specification. Service 0x0E is a get attribute single, and 0x10 is Set Attribute single.

Class, Instance, and Attribute are for the CIP objects on the compactcom. See chapter 10 CIP Objects in the EtherNet/IP user guide. The supported services are also listed.

You are most likely seeing an issue related to the process state. With only a class 3 explicit message the compactcom is not moving into process active.