Multipoint indicator tagging convention?

[ControlsPartner]

Hello friends. Just found this forum. I have 8 pressure transmitters on the same segment. Tagnames PT-1 through PT-8. There is a field local indicator that can read any of the eight signals. What letter tag do you give it?

I have to give it a unique number say 20, since it doesn't belong to any one of the 8 transmitters (regardless of location). So I can't call it a PI (since it's multipoint). Since it is a multipoint indicator, can I tag it a PUI-20? Since U is a multivariable?

Any help is appreciated! :)

[rezabejd]

The instrument tag serves a variety of purposes, but everyone uses them in their own style, or so it appears. I worked in a plant where it was common to have alpha-prefixes of 4 or more letters, as in "FRCIT-60103". Once the control system was converted to DCS, the long tags had to go away - early DCS only supported eight characters or so.

For me, "UI" would be fine. Our practice is for the hundreds digit to follow the service as well (a practice we picked up from the 60's-vintage Fluor job described above), so, for example, your PT's would be PT-xx301, 302, 303 etc. (where xx was a plant area designator). One could call multi-indicator "UI-xx300"

I forget which standard this is - S22 maybe? But I've yet to see a job where it was followed prescriptively. Not sure the "U" has the same meaning as a "succeeding" letter though, but if you want a "PUI" I think you're free to use it.