This article is about a "BadCommunicationError" when trying to establish a connection with the OPC-UA client UaExpert to your Anybus CompactCom IIoT Secure module as OPC-UA server.
In UaExpert, when you try to add your Anybus CompactCom IIoT Secure module as a server, instead of getting a list of available endpoints you end up with a "BadCommunicationError":
AB6650-C, Anybus CompactCom for PROFINET M40 IIoT Secure
AB6651-C, Anybus CompactCom for EtherNet/IP M40 IIoT Secure
AB6689-C, Anybus CompactCom for PROFINET B40 IIoT Secure
AB6690-C, Anybus CompactCom for EtherNet/IP B40 IIoT Secure
AB6750-C, Anybus CompactCom for PROFINET M40 IIoT Secure without housing
AB6751-C, Anybus CompactCom for EtherNet/IP M40 IIoT Secure without housing
The application note "Enabling and Using OPC UA on Anybus CompactCom 40 IIoT Secure" describes the steps necessary for a connection with UaExpert. In short, both the OPC-UA client and server need to trust each other by installing their respective certificates in order to set up a secure connection.
Therefore, by means of the Anybus Certificate Generator, you need to:
- Create a CA (certificate authority) certificate (unless you already own one from a third party)
- Create a device certificate stemming from the CA certificate and install it to your Anybus CompactCom IIoT Secure
- Install the UaExpert application certificate and install it to your Anybus CompactCom IIoT Secure
- Install the device certificate (from step 2) in UaExpert
POSSIBLE CAUSEWhen working out step (2), generating the device certificate in the Anybus Certificate Generator, it is vital that you strictly adhere to the following rules when filling out the fields for Common Name (CN) and Alternative Name (URI).
Thus, the default value of the Alternative Name (URI) can either contain the network hostname or the module's serial number:
An example for the Alternative Name (URI) in case you didn't attribute a network hostname is
like in both screenshots below
You can find out the serial number of your Anybus CompactCom IIoT Secure on the sticker or by reading out attribute #3 of the Anybus object #1.
- When you are finally able to chose your endpoint and connect to the OPC-UA server from UaExpert, you'll get this error message, which you may safely ignore:
- Reading out the serial number by the application:
How to read out information from an Anybus CompactCom during initialization?