Electric signal
ISA 5.1-2009/2022 (instrument line symbols)
Drawn as
A thin dashed line.
Meaning
Analog (4-20 mA) or discrete electrical signal between instruments, DCS, PLC and SIS. It shows the loop, not a cable route. Not modelled.
Variants
- ISA 1984 drew electric signals as a dashed line too; very old drawings use ///
- Some legends draw binary (on/off) electric signals with a different dash pattern
Not physical hardware. Read it, then skip it in the 3D model.