# IEC two-wire PLC point: in, 1st point, 2 wires Canonical URL: https://eloragrid.ai/symbols/iec-two-wire-plc-point-in-1st-point-2-wires Publisher: Elora Grid Updated: 2026-10-28 Lookup label: PLC Drawing use: Schematic Reference families: IEC, Manufacturer ## Symbol convention Convention: IEC Form: IN, 1st Point, 2 Wires Autodesk IEC-60617 Symbol Preview: PLC I/O, PLCIOI2T / PLCIOI2TV. This identifies the publisher's library context; exact IEC graphics and database identities are not asserted. Two-wire PLC point form: IN, 1st Point, 2 Wires. ## In plain English ### What does IEC two-wire PLC point: in, 1st point, 2 wires mean? A two-wire PLC point form shows two terminal connections associated with a controller input or output point. The symbol is an interface reference, and the module data must establish whether the connection is digital, analogue, isolated or part of a shared common group. This entry identifies the in, 1st point, 2 wires form in the publisher's IEC-context family. ### A simple example When tracing a field device to a PLC terminal strip, identify the rack, module, channel and both terminal numbers. Follow the common or return conductor as carefully as the signal conductor so a technician can reconcile the schematic with the module wiring sheet. The two-connection interface must be read with the load and supply arrangement. Leakage current and minimum load can matter where a powered device is connected in series with an input. ### What the drawings help you do Two drawn wires do not prove that the field device is loop-powered or that a point can supply current. Electrical type, polarity, common grouping and internal protection depend on the selected module and cannot be inferred from the outline. ### This particular reference Two-wire PLC point form: IN, 1st Point, 2 Wires. This entry adds the in, 1st point, 2 wires detail to the broader two-wire PLC point family. Two drawn wires do not prove that the field device is loop-powered or that a point can supply current. Electrical type, polarity, common grouping and internal protection depend on the selected module and cannot be inferred from the outline. ### Terms - Terminal: An identified point where a conductor connects. - Signal: Electrical information passed between devices, rather than necessarily the main power supply. - Rating: A value stating the conditions for which equipment is specified. Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram. - [PLC input and output point symbols](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-16A484BE-F73C-4612-8D12-E760E981C4E9.htm) ## What it represents A two-wire PLC point form shows two terminal connections associated with a controller input or output point. The symbol is an interface reference, and the module data must establish whether the connection is digital, analogue, isolated or part of a shared common group. This entry identifies the in, 1st point, 2 wires form in the publisher's IEC-context family. When tracing a field device to a PLC terminal strip, identify the rack, module, channel and both terminal numbers. Follow the common or return conductor as carefully as the signal conductor so a technician can reconcile the schematic with the module wiring sheet. The two-connection interface must be read with the load and supply arrangement. Leakage current and minimum load can matter where a powered device is connected in series with an input. Two drawn wires do not prove that the field device is loop-powered or that a point can supply current. Electrical type, polarity, common grouping and internal protection depend on the selected module and cannot be inferred from the outline. ## How to read it - The two-connection interface must be read with the load and supply arrangement. Leakage current and minimum load can matter where a powered device is connected in series with an input. - Two drawn wires do not prove that the field device is loop-powered or that a point can supply current. Electrical type, polarity, common grouping and internal protection depend on the selected module and cannot be inferred from the outline. ## Information to show or reference - Identify controller, module and channel address. - Label both terminals and the shared common where used. - Reference signal type, polarity and module wiring documentation. ## Important distinction This entry adds the in, 1st point, 2 wires detail to the broader two-wire PLC point family. Two drawn wires do not prove that the field device is loop-powered or that a point can supply current. Electrical type, polarity, common grouping and internal protection depend on the selected module and cannot be inferred from the outline. ## Facts - Drawing form: IN, 1st Point, 2 Wires - Public vendor block names: PLCIOI2T / PLCIOI2TV. Autodesk identifiers, not standards database IDs. - Drawing purpose: two-wire PLC point - Graphic scope: Independently authored educational illustration; not certified standard geometry, a terminal pinout or a product footprint. ## Public references - [PLC input and output point symbols](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-16A484BE-F73C-4612-8D12-E760E981C4E9.htm) — Autodesk. Public PLC I/O table explicitly lists PLCIOI2T / PLCIOI2TV with this operating or connection form. Vendor graphics are linked, not copied. ## Graphic scope Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.