SLC 5/5 and 5/3 over internet interface

i have local scada without rslinx gateway which connected to 4 SLC5/3 [they connected to each other but DH485 and by converter to be RS232 to be connected to the SCADA] and i want over internet to connect to PLCs and i got an idea but i dont know if it works or not which is to get a rs232 splitter and a PC with rslinx gateway so i dont make an interruption to the local SCADA can anybody helps me

The computer is using DF1 Full Duplex protocol over RS-232 to communicate with the DF1/DH485 converter.

The problem is that DF1 Full Duplex is a point-to-point protocol; there is no way to determine which PC would be able to transmit (and indeed, which would receive) data through a serial splitter.

I can think of a handful of solutions for this problem:

1. Install RSLinx Gateway on the SCADA PC and allow it to be the route through which you connect to this DH485 network.

2. Install a second PC with its own RS232/DH485 or even USB/DH485 interface, along with RSLinx Gateway, to be the bridge between a TCP/IP network (almost certainly a VPN, not the Internet itself) and the DH485 network.

3. Use a standalone Ethernet/DH485 gateway from EquusTek (aka DataLink aka protocolconverter.com).

4. Use an Allen-Bradley 1756-series chassis with a 1756-ENBT and a 1756-DH485 module.