Other peer-to-peer examples you'll find on the forums provide various options for moving data via Ethernet, but what if you only have a serial connection, for example, to a really old controller?
Here's how one of our long-time customers, with a big variety of Opto 22 hardware, started moving data into his PAC, using just a little logic. He's got:
...controller running Factory Floor. The program is simple: I configure com1 (2 wire 485) with the configure port "com1:38400,n,8,1" and made a loop with a delay to Transmit table via serial port... an integer table with a length of 28.
On his PAC, he uses a comm handle, similarly configured, just looping to receive that same table.
Ta-da! Data from old controller now in PAC and read to groov! Of course, for data to be written, you could just add another chart to go the other way -- with the PAC doing the Transmit and the FF Controller doing a receive. Easy as π (pi).