Let me clarify on what I'm trying to do here. I am trying to write a program that can browse the modules on a controllogix rack. After the modules are discovered at whichever port/address combination I want to be able to browse that module to see what device is connected to it.
Example: I have a 1756 DHRIO module on my controllogix rack. Attached to the DHRIO module is a PLC5 controller. The connection is a blue hose cable (DH+) on channel A of the DHRIO. I sent a GetAttributeAll service to each address on port 1. That successfully showed me all the locations of my modules on this rack. Now I know what modules are on this rack, I want to continue to browse further down the modules to see what devices are connected on the other end. How could I do it? What commands could I send to query the module to retrieve the end device? I've noticed through wireshark that RSLogix sends a GetAttributeAll command to retrieve the connection status on Channel A of the DHRIO module. The class code used in this call is A4h, which is why I'm trying to find out what this class code is and what attribute is available for me to use.