Configuring Ignition OPC Tag Creation and Default Server

Overview of Ignition OPC Tag Creation

Inductive Automation's Ignition by Inductive Automation uses a unified tag database that bridges OPC UA servers, PLC devices, and derived expressions. Tags are created in the Ignition Designer under a Tag Provider, then bound to an OPC server connection or computed expression. Because the Designer exposes the full OPC UA address space, every tag must reference a configured server, an OPC item path, a data type, and an optional data format. The default behavior when none of these are pre-filled has historically required two layers of menu navigation before a usable OPC tag exists, which is the root friction this workflow addresses.

The native OPC UA server bundled with every Ignition Gateway is named Ignition OPC UA Server and listens on opc.tcp://<host>:<port>. Operators building tags against the gateway's internal server typically have only one configured connection, so hard-coding a default to Ignition OPC UA Server removes a repetitive selection step. For sites with multiple server connections, the safer pattern is to initialize the property to the first alphabetically valid configured server rather than to a fixed string, preserving the dropdown behavior for power users.

This technical reference consolidates the official guidance from the Inductive Automation Ignition OPC UA Module documentation with practical patterns for streamlining tag creation, leveraging the Tag Browser, and configuring UDT parameter binding for parameterized tags.

Prerequisites

1. Ignition Gateway 8.0 or later. The Tag Browser integration in the tag editor and OPC UA discovery improvements shipped with the 8.x line; earlier 7.x branches require manual server selection in a dropdown.
2. OPC UA Server module licensed and active. The native Ignition OPC UA Server only appears when the OPC UA Server module is enabled on the gateway. On Ignition Edge 7.9.x the OPC UA server is internal-only and is not exposed to external clients; the official module documentation confirms external access requires Ignition Edge v8 and a valid license.
3. Configured OPC UA server connection. At least one entry under Config > OPC UA > Server Connections must exist. The default server field is populated from this list.
4. Designer with a Tag Provider. A tag provider (default or custom) must be present in the project. The Designer stores OPC tags beneath a folder structure inside that provider.

OPC Tag Creation Workflow: Step-by-Step

Step 1 - Open the Tag Editor

In the Ignition Designer Project Browser, expand the Tag Provider, right-click the destination folder, and choose New Tag > OPC Tag. This opens the tag editor dialog. For the standard OPC tag type the editor exposes the following primary fields:

Step 2 - Use the Tag Browser to Populate OPC Server and Item Path

The Tag Browser, accessible from the tag editor's item path field, was added to provide keyboard-friendly tag discovery. Selecting a node in the browser simultaneously populates:

• The OPC Server field with the server connection that owns the address space.
• The OPC Item Path field with the fully qualified browse path.

This eliminates the most error-prone manual entry step. Operators who previously typed Ignition OPC UA Server into the server field for every tag benefit from auto-population as soon as a browser node is clicked. See the Tags in Ignition video at Inductive University for the canonical walkthrough.

Step 3 - Confirm Data Type and Data Format

The default data type is Integer for legacy reasons. When dragging a tag from an OPC browser, the Designer should infer the data type from the node's value attribute where available. For strict projects, set the data type explicitly and choose a matching Numeric Format in the Data Format tab. The Creating OPC Tags Manually video demonstrates type-aware creation including Real scaling and Boolean bit selection.

Step 4 - Bind to a Tag Group and Apply Quality Overlay

Tag Group selection determines the evaluation rate and deadband. For high-frequency PLC tags use a custom group with 5 Hz or 10 Hz rate; for slow status tags the default group at 1 Hz is sufficient. Enabling the Quality Overlay tag property propagates Good / Bad / Uncertain quality codes to clients so HMI components can render bad data without scripting.

Default Server Selection Logic

When the OPC server field is left blank, the Designer traditionally returns a validation error rather than substituting a server. Two programmatic behaviors have been requested by integrators to reduce clicks:

Field deployments strongly favor the second strategy. Hard-coding the string Ignition OPC UA Server creates failures on Edge platforms running 7.9.x and on any gateway where the operator renamed the default connection.

Quick-Create Patterns for Bulk OPC Tags

For sites that need to bring dozens or hundreds of tags online quickly, the following patterns reduce manual entry:

1. Drag-from-browser: Drag a node from the OPC Browser panel directly onto a folder in the Tag Browser. The Designer creates an OPC tag using the server inferred from the browser, the item path, and the type from the source node. This is the canonical method described in the Inductive University tag creation video.
2. Copy-paste tag of same type: Right-click an existing tag of the correct data type and choose Copy Tag, then Paste Tag. The Designer reuses the data type, format, and tag group; only the name and item path differ. This is the closest practical equivalent to the "last created tag of that type" template behavior requested in the field report.
3. UDT parameter binding: Define a UDT with an OPCItemPath parameter. When instantiating UDT instances, the parameter binding dialog pulls the static default value from the UDT definition, eliminating manual item path entry. This pattern is covered in the OPC UA module documentation under parameterized tag creation.

UDT Parameter Binding for Parameterized Tags

UDTs (User Defined Types) are the recommended approach when the same tag shape is replicated against multiple PLCs or devices. Configure the UDT as follows:

UDT Definition: Valve_Template
  Parameters:
    - OPCItemPath (String, default = "[Device]Valve1")
  Members:
    - Command (OPC Tag, bound to {OPCItemPath}/Command)
    - Status  (OPC Tag, bound to {OPCItemPath}/Status)
    - Fault   (OPC Tag, bound to {OPCItemPath}/Fault)

When the operator creates an instance of Valve_Template, the parameter prompt prefills with [Device]Valve1. Override the value at instance creation time and the Designer rewrites the bound OPC paths automatically. This addresses the legacy complaint that the parameter binding dialog did not pull over static defaults; that behavior is now standard in 8.x.

Keyboard-Friendly Tag Editor

The legacy tag editor used mouse-driven tab navigation that did not respect field order. The updated 8.x tag editor improves on this by:

• Accepting Tab between Name, OPC Server, and OPC Item Path in the expected order.
• Opening the Tag Browser directly from the OPC Item Path field via F4 or the inline browse button.
• Closing the browser and returning focus to the OPC Item Path field upon selection.

For high-volume commissioning work, configuring the Designer keyboard mapping under File > Preferences > Keyboard to bind Ctrl+Shift+N to "New OPC Tag" accelerates repetitive creation.

Verification Checklist

After deploying the streamlined workflow, verify each tag using the following checklist:

1. Open the Tag Browser and confirm the new tag appears under the correct folder.
2. Right-click the tag and select View > Diagnostics. Confirm Quality = Good and Value matches the live PLC value.
3. Subscribe to the tag from a client window and verify it updates at the configured tag group rate.
4. Force the OPC server offline and verify the tag's quality transitions to Bad_CommunicationError (code 0x80050000) within two evaluation cycles.
5. Restore connectivity and confirm the tag returns to Good without manual intervention.

Troubleshooting Matrix

Field-Proven Caveats

FAQ