Off-Page Connector

Off-Page Connectors (OPCs) are PID shape components that represent interruptions in piping — connecting pipes from one P&ID to another, or to another part of the same P&ID. When the Fluidstream Simulation reaches an Off-Page Connector, fluid automatically continues to its paired Off-Page Connector.

In pharmaceutical facilities, Off-Page Connectors are essential for modeling multi-drawing systems — connecting a CIP supply header on one P&ID to a process skid on another, or linking a WFI distribution loop across multiple drawings.

🏷️ Classification

Off-Page Connectors are classified as the Off-Page Connector behaviour in the P&ID Components Classification system. Each OPC class defines its binding behavior through class-level attributes.

🔗 Binding Methods

The binding method determines how two Off-Page Connectors find and pair with each other. This is configured at the class level and applies to all instances of that OPC class.

Match by tag (paired connectors with same tag)

The simplest binding method. Two OPCs are paired when their Bind values are identical.

Example: Two connectors on different P&IDs both labeled "Line-101" will automatically pair.

Point-to-point (directly linked pair)

A stricter binding method requiring mutual reference. OPC A's Tag must match OPC B's Bind, and OPC B's Tag must match OPC A's Bind.

Example: OPC-1 points to OPC-2, and OPC-2 points back to OPC-1. Both must agree.

One-way (fluid exits but doesn't return)

A directional binding where OPC A's Tag points to OPC B's Bind value (or vice versa), but only one direction needs to match.

Example: A source OPC sends fluid to a destination OPC without requiring the destination to reference back.

🖱️ OPC Connectivity Bullets and Hover Popup

AseptSoft provides a visual overlay that shows the connection status of every Off-Page Connector directly on the drawing, along with an interactive hover popup for inspecting and navigating OPC pairs.

🔵 Connectivity Bullets

When enabled, small colored circles appear at each OPC's position on the drawing:

These bullets give you an instant overview of your cross-PID connectivity status. You can scan the entire drawing and immediately spot any unconnected OPCs that need attention.

⚙️ Enabling the OPC Bullets

The feature supports three modes:

📋 What the Hover Popup Shows

Hover over any OPC bullet to see a floating panel with detailed connectivity information:

For a connected OPC:

For an unconnected OPC:

🧭 Cross-PID Navigation

The Navigate to Pair button is one of the most useful features when working with multi-page P&IDs:

1. Hover over a connected OPC

2. Click Navigate to Pair

3. AseptSoft automatically switches to the destination P&ID, selects the paired OPC, and zooms to it

This works across any number of open drawings in the same session — no manual searching or drawing switching required.

📊 Connectivity Graph

The popup also includes a Show Connectivity Graph button that opens a full visualization window showing the entire network of OPC connections across all open P&IDs. This provides a bird's-eye view of how your drawings are interconnected.

🧩 Multi-OPC Blocks

A single AutoCAD block can contain multiple Off-Page Connector sub-nodes. This is configured through the Symbol Style system, where each sub-node has:

Each sub-node creates its own Tag and Bind synthetic attributes, allowing independent pairing per connection point within a single block.

🌐 Cross-PID Fluid Flow

Off-Page Connectors are the mechanism for cross-PID fluid flow. When paired OPCs exist on different P&IDs, fluid can flow between drawings.

Cross-PID Stream Behavior

Pairing Logic

The system evaluates pairs based on the binding method:

• Match by tag: Both OPCs must have identical Bind values

• Point-to-point: OPC A's Tag must equal OPC B's Bind AND OPC B's Tag must equal OPC A's Bind

• One-way: OPC A's Tag must equal OPC B's Bind OR OPC B's Tag must equal OPC A's Bind

💧 Fluid Creation

The FluidCreation property allows an Off-Page Connector to generate fluid at its endpoint. This is useful when the OPC represents a connection to an external system where fluid originates, rather than simply bridging two P&IDs.

💊 Pharma example: An OPC representing a utility tie-in from a central WFI generation plant can be set with FluidCreation enabled, so that WFI fluid is injected at the connector without needing a separate Source component.

💊 Pharma Scenario: Connecting a CIP Supply Header Across P&IDs

Imagine a CIP system spanning two drawings:

• P&ID-001 contains the CIP skid with the caustic tank, acid tank, and supply pump.

• P&ID-003 contains a process vessel with its inlet/outlet manifold.

To connect them:

1. On P&ID-001, place an Off-Page Connector at the end of the CIP supply header with Tag = "CIP-SUPPLY-003" and Bind = "CIP-SUPPLY-003".

2. On P&ID-003, place a matching Off-Page Connector at the start of the CIP inlet with Bind = "CIP-SUPPLY-003".

3. Set the binding method to Match by tag.

4. When both PIDs are open, the Fluidstream Simulation will carry CIP Caustic from the skid on P&ID-001 through the OPC pair and into the vessel manifold on P&ID-003.

This same approach works for WFI distribution loops, clean steam headers, and any other utility that spans multiple P&IDs.

🏭 Workflow: Tracing a Cross-PID Fluid Path Using OPC Bullets

When debugging fluid flow issues across multiple drawings, the OPC bullets and hover popup provide a fast way to trace connections:

1. Enable OPC bullets in Auto mode

2. Look for red bullets — these indicate unconnected OPCs that may be blocking cross-PID flow

3. Hover over a green bullet to confirm the connection — verify the partner PID and Tag match your expectations

4. Click Navigate to Pair to jump to the destination P&ID and confirm the paired OPC is correctly placed

5. Run a Fluidstream Simulation to verify fluid flows through the OPC pair

6. If a bullet is red, hover over it to see the list of other unconnected OPCs — you may find a misspelled Tag or Bind value that's preventing the match

💡 Quick troubleshooting tip: If fluid isn't flowing across P&IDs, start by checking the OPC bullets. Red bullets immediately show you where the break is. Hover over the red OPC to see its Tag and Bind, then compare with the intended partner.

⚙️ Configuration

For defining and connecting Off-Page Connectors, refer to the Activation Settings in the classification system.

Class-Level Attributes

Instance-Level Attributes

🛠️ How To: Set Up an Off-Page Connector Pair

1. Classify the OPC block as Off-Page Connector in the P&ID Components Classification window.

2. Set the Binding Method to the appropriate mode (Match by tag for simple pairing, Point-to-point for strict pairing, One-way for directional flow).

3. Configure the Bind Build token pattern so AseptSoft knows how to read the pairing identifier from the drawing.

4. Place matching OPCs on each P&ID with consistent Tag/Bind values.

5. Open both PIDs in the same module and run a Fluidstream Simulation to verify cross-PID fluid flow.

6. Enable OPC bullets to visually confirm all connections — green means connected, red means something needs fixing.

🔗 Related Pages

• Engineering Item — Controllable components connected via OPCs

• Source — Fluid origins that may feed into OPCs

• Fluidstream Simulations — Cross-PID fluid flow visualization

• PID Shape Components — All shape component types

• P&ID Components Classification — Classifying OPC blocks

• Activation Settings — Detailed OPC configuration

• Valve Hover Inspector — Similar hover inspection feature for valves