Can any ProLinx module support COM to SLC5/05 and 3 serial devices? How can I connect more than one DF1 device to an Allen-Bradley processor's channel 0 port? Need to use the serial port on a SLC50

For this type of application, your customer can use the ProLinx gateway. 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.