Terminal
Terminal connection
An identified electrical connection point linking schematic and wiring information.
Schematic
Symbols · PLC I/O
PLC input / output
A controller interface point connecting field signals to an identified module channel.
Schematic · PLC I/O
What it represents
A PLC input or output point connects a field signal with a controller module and channel. Input and output, digital and analogue, and one-wire or multi-wire arrangements are distinct characteristics. The module specification establishes electrical behaviour and terminal information.
A schematic should connect channel identification to the I/O schedule and field device. Shared supplies, commons and isolation boundaries require their own documentation. A generic controller box is not a pinout or wiring instruction for a particular module.
How to read it
- Identify module, channel and signal direction.
- Use the selected module documentation to interpret supply, common and terminal requirements.
Information to show or reference
- Match the I/O schedule.
- Identify signal type and channel reference.
- Link module terminals and field-device documentation.
A distinction that matters
An input point, output point and communications connection are different interfaces. A generic box cannot establish their electrical compatibility.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
PLC input and output point symbols
Public input/output point and wiring-count categories.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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