Instrument behind the panel (not accessible)
ISA 5.1-2009/2022 (general instrument and function symbols)
Drawn as
A circle with a dashed horizontal line across the middle.
Meaning
Function not normally accessible to the operator: behind the panel, in a marshalling cabinet or rack room (relays, converters, signal isolators). Not modelled.
Variants
- Circle-in-square with a dashed bar = a DCS function not shown to the operator (internal calculation)
Tags
FY · PY · TY
Not physical hardware. Read it, then skip it in the 3D model.