PLC I/O
PLC input / output
A controller interface point connecting field signals to an identified module channel.
Schematic
Symbols · DO RELAY
PLC relay output
A PLC relay output switches a documented contact path through the module's relay interface.
Schematic · DO RELAY
What it represents
A PLC relay output switches a documented contact path through the module's relay interface. The load supply and contact common may be separate from the PLC electronics supply.
How to read it
- Trace the load source through the output contact and common terminal.
- The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation.
Information to show or reference
- Identify output channel
- Show load supply/common
- Reference contact/load rating
A distinction that matters
A relay output is a contact interface, not a transistor output with the same supply/common behaviour.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Modicon TM3 digital I/O hardware guide
Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic.
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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