How can I connect more than one DF1 device to an Allen-Bradley processor's channel 0 port. You will need to use the serial port on a SLC505 to talk to 3 devices. Two of them are MicroLogix over radio modems. The 3rd is a medina telemetry unit which supports DF1 point-to-point only. For this type of application, your customer can use the ProLinx gateway 4102-DFS3-DFM This gateway is a multiplexer between one slave DF1 device and 3 master devices. You will have to connect the SLC505 serial port to the master port of the ProLinx and use the 3 others ports to connect the 2 MicroLogix stations and the medina telemetry.