Glossary
Plain-language definitions of the terms that show up in loop diagrams and schedules.
A signal type that reads a continuous process variable, typically 4–20 mA, into a controller.
A continuous output signal a controller uses to position a device such as a control valve.
A list of field cables with origin, destination, core count, and the loop tags they serve.
A two-state input carrying a status, such as a switch or alarm contact.
A two-state output used to energise a solenoid, lamp, or motor starter.
A printed wire marker, usually a sleeve, whose text matches the wire number on both ends of the conductor.
A wire list with each conductor, source device and pin, destination device and pin, colour, and cable. SchematicForge does not yet export this as a project CSV.
A reference designation standard for industrial systems. SchematicForge keeps the tags you supply; it does not retag the plant to 81346.
A master list of every instrument tag on the project, usually with service, P&ID, and location.
The spreadsheet of instrument tags and I/O types that drives loop diagrams, the register, and the schedules.
Junction box — a field enclosure where instrument cables terminate before running back to the marshalling area.
The complete instrument circuit from field device to controller: sensors, transmitters, cables, terminations, and the controller channel.
Site verification of a loop: as-found and as-left readings. Not a signed FAT certificate.
A drawing showing one instrument loop in full, with every signal, termination, and controller interface annotated.
The cabinet in the control room where field cables terminate and are jumpered to controller I/O cables.
A row of terminals inside a marshalling cabinet assigned to one field cable or group of signals.
The engineering-unit values mapped to the bottom and top of a signal span, e.g. 0–10 bar.
A version letter or number on a drawing. Changing a loop creates a new revision rather than overwriting the old one.
One input or output within a loop. A loop can carry several signals, each with its own cable, card, and channel.
The unique identifier of an instrument, e.g. PT-1001 for pressure transmitter 1001.
A document listing every terminal connection in a JB or cabinet, with wire numbers and destinations.
The boxed area of a drawing carrying project, tag, drawing number, and revision information.
The supply voltage of a loop, such as 24 VDC, governing device and barrier selection.
The identifier printed on a conductor and on the loop sheet. Stored per signal; uniqueness is checked inside a loop.