I am hoping to develop a PIC based system soon which will be Ethernet based with a requirement to communicate with a HART Transmitter. I guess I have two options on the HART side, i.e. use a ready built HART modem and hook this up to a RS232 level shift circuit or use a HART modem IC direct.
Is it still possible to buy HART Modem ICs (e.g. 20C15) or are these pretty much obsolete these days ? If they are obsolete, what are the other options ?