AutoCAD Electrical Connectors: Point-to-Point Wiring Made Easy

AutoCAD Electrical Connectors: Point-to-Point Wiring Made Easy (Updated July 2026)

If you've worked through AutoCAD Electrical's schematic module and panel layout, you may have noticed a different wiring documentation style appearing in industrial automation drawings: point-to-point connector diagrams. Where ladder-style schematics show circuit logic top-to-bottom, point-to-point diagrams show how individual wires connect from one device connector to another — pin 1 of connector X5 on the PLC to terminal 14 of relay K3, for example. AutoCAD Electrical's Connectors module is specifically built for this kind of documentation. It's the right tool for PLC I/O wiring, SIMATIC system connections, and connector-heavy panels where individual pin-to-pin traceability matters. This guide explains what connectors are, how the connector library works, and how to create and document point-to-point connections.

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What Are Connectors in AutoCAD Electrical and When to Use Them

In AutoCAD Electrical, a connector is a multi-pin device that creates and manages point-to-point wiring connections. A connector symbol represents the physical plug or socket (like a D-sub connector, a terminal block row, or a PLC I/O module header) and lists each pin with its wire number, signal name, and destination. The Connectors module handles two things: the visual representation of connector symbols in the drawing, and the internal database that tracks which pin of which connector is connected to which pin of which other connector across the entire project. This makes it possible to generate an accurate point-to-point wiring list that tells an assembler: connect Pin 4 of connector X5 to Pin 14 of connector X12, using 0.5mm² red wire.

Point-to-Point Wiring vs Ladder Diagrams — When Each Is Used

Ladder-style schematic diagrams are the standard for showing circuit protection, switching logic, and control sequences — they're the primary documentation for control panels. Point-to-point wiring diagrams are used when the documentation need is specifically about physical connections at the connector or terminal level: PLC I/O modules where each input and output needs individual wire documentation, servo drive cabling where the connector pinout from the drive to the motor encoder matters, and connector harnesses in machine cabinets where 37-pin D-sub connectors carry mixed signals. Some projects use both: ladder diagrams for the circuit logic, and a separate connector document for the PLC I/O wiring and harness routing.

The AutoCAD Electrical Connector Library and SIMATIC Connectors

AutoCAD Electrical's connector library is a collection of pre-built connector symbols for common industrial connectors. The library includes SIMATIC connectors (Siemens PLC I/O system connectors), standard D-sub connectors (9-pin, 15-pin, 25-pin, 37-pin), circular industrial connectors (M8, M12, Harting Han), and terminal block row connectors. SIMATIC connectors are particularly relevant for projects using Siemens S7 PLC systems — the SIMATIC sub-library includes the correct pinout representations for S7 digital and analog input/output modules, so you can document the I/O wiring directly from the module's pin layout. AutoCAD Electrical also supports importing custom connector pinout data from manufacturer files.

Parametric Symbol Generation — How Connector Symbols Are Built

The key feature of AutoCAD Electrical's connector module is parametric symbol generation. Instead of drawing each connector symbol manually (which would require drawing a different symbol for every 4-pin, 8-pin, 12-pin, 16-pin connector variant you use), parametric generation lets you specify the number of pins and AutoCAD Electrical builds the correct symbol automatically. You define: connector type (male/female), number of pins, pin spacing, and orientation. AutoCAD Electrical generates the connector symbol with the correct number of pin attributes, in the correct layout, ready for wire connections. This is consistent with how the rest of AutoCAD Electrical handles symbols — the symbol builder works parametrically so each instance can have different pin counts without requiring manually drawn symbol variants.

Creating a Point-to-Point Connection in AutoCAD Electrical

To create a point-to-point connection in AutoCAD Electrical: insert the first connector symbol (source) from the Connector library into your drawing. Insert the second connector symbol (destination). Use the 'Draw Wires' or 'Connect' tool to draw a wire from a pin on the source connector to a pin on the destination connector. Assign a wire number to the connection. AutoCAD Electrical records both the wire number and the connection (from connector A, pin 3 to connector B, pin 7) in the project database. When you generate the connector wiring report, this connection appears as: 'Wire 103 — from X5/pin 3 to X12/pin 7 — 0.5mm² red'. Repeat for each pin-to-pin connection in the connector diagram.

Connector Reports and Wiring Documentation

AutoCAD Electrical can generate connector-specific reports: Connector Report (all connectors in the project with their pin assignments), Connector Wiring Report (full point-to-point wire list by connector), and Missing Pin Report (pins in a connector that have no wire assigned — useful for confirming you've documented all connections). These reports are accessed from the Project Reports dialog, same as the regular BOM and wire list. The Connector Wiring Report is the document that the harness assembly team uses to build wiring harnesses before they go into the panel — it's the cable equivalent of the panel layout drawing.

Connectors in PLC I/O Documentation: A Practical Example

A typical PLC I/O wiring documentation scenario: you have a Siemens S7-1200 PLC with a 16-input digital I/O module. Each input connects to a field device (sensor, switch, pushbutton) via a 2-wire connection. In AutoCAD Electrical, you insert the SIMATIC SM1221 (16DI) connector symbol, which shows all 16 inputs plus commons. For each input, you draw a wire to the corresponding field device terminal. The connector documentation becomes a complete I/O list: Input 0 (connector pin I0.0) connects to proximity sensor B1 at Terminal X2-1; Input 1 (pin I0.1) connects to limit switch S5 at Terminal X2-3; and so on. This is exactly the documentation that commissioning engineers use during machine startup to verify every sensor input is correctly wired and active.

FAQs

What is the difference between a connector and a terminal in AutoCAD Electrical?

In AutoCAD Electrical terminology: a terminal is an individual connection point in a terminal block (usually a screw or spring terminal that accepts one or two wires from each side). A connector is a multi-pin plug or socket assembly where multiple signals are grouped in one physical housing (like a 9-pin D-sub or a 20-pin PLC I/O module header). Terminals are documented using the Terminal Report, which groups them by terminal strip designation. Connectors are documented using the Connector Report, which groups them by connector designation (X1, X5, CN3, etc.). Both represent physical wiring connection points, but at different physical scales — a terminal is one wire in, one wire out; a connector is a housing containing many pins, each of which is a separate connection point.

Can I use AutoCAD Electrical connectors for Siemens PROFIBUS or PROFINET documentation?

PROFIBUS and PROFINET are network-level protocols, not point-to-point wiring at the individual signal level — PROFIBUS uses a 9-pin D-sub connector (which AutoCAD Electrical can document with a standard D-sub connector symbol) and PROFINET uses RJ45 or M12 connectors. The actual PROFIBUS or PROFINET network topology documentation (which devices are on the network, network addresses, segment lengths) is done in Siemens TIA Portal network view, not in AutoCAD Electrical. AutoCAD Electrical handles the physical wiring documentation — the 9-pin D-sub connector from the PLC's MPI/PROFIBUS port to the HMI, for example — but the network configuration itself lives in TIA Portal.

How many pins can a parametric connector symbol have in AutoCAD Electrical?

The parametric connector symbol generator in AutoCAD Electrical can handle connectors from 1 pin to 99 pins in a single column orientation, and up to 50 pins per column in dual-column orientation. For very large connectors (DIN rail multi-pole terminal blocks with 100+ positions), it's common practice to break the connector into multiple segments across sheets and use cross-references to link the segments. The practical limit for readability is 32–40 pins per connector symbol on an A3 drawing at 1:1 scale before the symbol becomes too compressed to read clearly on a printed drawing.

Is the AutoCAD Electrical connector module part of the standard AutoCAD Electrical licence?

Yes, the Connector module is included in the standard AutoCAD Electrical licence — it is not a separate add-on. All features discussed in this tutorial (connector library, SIMATIC connectors, parametric symbol builder, connector reports) are available in the full AutoCAD Electrical installation. Access the connector tools from the Panel tab in the ribbon, under the 'Connectors' panel group. If you have AutoCAD Electrical installed but don't see the Panel tab, go to the Workspace dropdown (top right of screen) and switch to the 'AutoCAD Electrical' workspace, which shows all three tabs: Schematic, Panel, and Reports.