There has been a lot of chatter about connecting to processors through an Ethernet to serial conversion unit. So, I thought I would provide some information on the topic.
The OPC-UA SLC driver supports multiple protocols and the protocol is determined in the following way:
If the connection path is blank (empty), it will first try CSP protocol on port 2222. If an error is received it will then try EIP protocol on port 44818 (this is the protocol used for the NET-ENI interface). The driver will keep trying each protocol until a successful connection is made.
If the connection path is used, the driver will use only EIP protocol on port 44818 and is intended for connection through a DHRIO module residing in a ControlLogix gateway.
Serial DF1 protocol is not supported, so a straight Ethernet to serial converter will not work with the OPC-UA SLC driver. The device must support Serial DF1 protocol for the serial connection to the processor and either CSP or EIP on the OPC-UA side. Although, CSP is typically only used for a processor directly connected through Ethernet.
We have customers that are using Moxa and it works fine to communicate to both the SLC and MicroLogix processors. I am finding out the model number of the Moxa unit and will post in this forum.
Usually, it is a matter of configuring the unit for the correct protocols, station numbers, etc.