Purely anecdotal data, so you can take it for what it's worth.
The process instrumentation distributor I worked for (USA) sold
- about 3 Profibus PA instruments per year and all were for replacements for equipment skids manufactured abroad and shipped to the US.
- between 4,000 to 5,000 HART instruments per year
- zero Foundation Fieldbus (FF) instruments until 2021 when a oil/gas supplier in the US won a contract for their systems in Asia and we dealt with about 600 FF transmitters.
As part of tackling the task of assigning a physical node address and a Physical Device (PD) tag on each of these FF transmitters, I discovered that there is a real lack of Foundation Fieldbus instructional material. A colleague who had earlier worked for a competitor told me that they geared up for the FF revolution in the mid-'90's that never materialized. Very few US companies took the leap into FF. They sold 3 FF systems over a 3 year period. A day or two after that conversation he looked me up to tell me that he had checked back with his former company and discovered that one hose '90's FF projects at a local process plant was now coming round because the plant was ripping out all the FF and going back to home run wiring and HART. The reason was the complexity of FF. What would be minor efforts to make changes-over-time, adding or deleting points, became major engineering tasks. The techs who had been trained at considerable expense in the 1990's were gone and trying to hire replacement techs with FF experience that could keep an aging FF network running was impossible.
I remember attending a local ISA meeting in the '90's with a speaker touting FF and I asked how the network was supposed to be maintained - there was no resources written at a tech level to explain operation and maintenance. The response was a shrug because my question didn't fit the sales narrative of "less expensive wiring" and "more diagnostics".
Fora like this occasionally got the spiel that one of the advantages of FF was that commissioning loop checks were no longer required because "everything could be done centrally from a keyboard" and "all that's been supplanted by the communications functions." There's an hour long Youtube FF video by BCIT with Ian Jappy
https://www.youtube.com/watch?v=yi_BsNEG55U
that puts that lie to bed - his commissioning checklist for a single point is a full page long checklist, including the ever-so-common "loop capacitance check" (8:18 to 9:30 on the video) and the wave form check. The issue isn't so much making the check but what do you do when the waveform is not ideal? Where's that intellectual property documented?
The instrutment manufacturer had no one in the US who knew anything about FF, other than it was a coded option in the part number. Zip. Nada. That was a stumbling block.
I produced a 35 slide power point illustrating the steps to configure the PD tag and node address with a Softing FF modem and Pactware. Arcane is the only word I can use for the number of clicks needed to do something so basic.
HART has its complexities, too, especially when used for comm, rather than comm for configuration. On another forum, there's a guy who can't get his HART 5 HART-enabled PLC I/O to talk to a supposedly backwards compatible HART 7 field transmitter. That's changes-over-time.
If you choose to dabble in Foundation Fieldbus realize that there's a whole new vocabulary to deal with. And you might want to check out exactly what resources you will have access to. Every thing as a manual but is it even half way intelligible to the novice?
