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-4060-F 4-Channel Relay Output Module with Modbus, 150 x 85 x 51mm (LWH) $171.20 Select