Advantech ADAM-4520-F Isolated RS-232 (DB9) to RS-422 (4-Wire)/485 (2-Wire) Converter, 10-30VDC, Revision EE $112.40 Select
Advantech ADAM-4019+-F Remote I/O Module, 8-Channel Universal Analog Input Module, ADAM-4000 Series $438.90 Select
Advantech ADAM-4510S-F Serial Repeater, RS-422/485 Repeater with Isolation, ADAM-4500 Series $195.30 Select