Produced/consumed tags are best treated as a defined controller-to-controller interface. Stable data structures, ownership, update expectations and loss-of-communication behavior should be designed before linking PLC application logic.
- Verify hardware, firmware and communication path before changing application logic.
- Use readable interfaces, ownership and diagnostic tags.
- Test normal, fault and recovery behavior.
- Keep a revisioned backup before production modifications.
Commercial Search Focus
Designed for engineers searching for Studio 5000 produced consumed tags, ControlLogix PLC to PLC communication, Rockwell troubleshooting, corporate training and integration/project support.
1. Engineering Overview
Produced/consumed tags are best treated as a defined controller-to-controller interface. Stable data structures, ownership, update expectations and loss-of-communication behavior should be designed before linking PLC application logic.
Who should use this guide: Rockwell programmers and integrators exchanging deterministic application data between Logix controllers. The practical objective is to create a documented PLC-to-PLC interface that fails predictably when the producer or network is unavailable. This makes the page useful for both learning and commercial plant work rather than only software navigation.
2. Architecture and Data Flow
The reference system is two supported Logix controllers connected over EtherNet/IP with a defined inter-controller data structure. Diagnose it by layers: field device/wiring, controller or server configuration, EtherNet/IP/data-server connection, application tags and logic, HMI/reporting layer, and operator workflow. The engineer should prove the failed layer before applying a workaround elsewhere.
| Layer | Engineering Check | Evidence |
|---|---|---|
| Hardware | Power, wiring, device/module state | LEDs, meter, device diagnostics |
| Communication | Address, route, connection, shortcut | Browse/path/quality status |
| Application | Command, permissive, state, ownership | Online tags, cross reference, trend |
| Operator/Data | Security, display, alarm, history | Client/server logs and runtime tests |
3. Prerequisites and Design Inputs
- A licensed engineering workstation with the required Rockwell software installed
- A training controller or approved offline project matching the target platform
- EtherNet/IP addressing, device names and a basic I/O/network drawing
- A current project backup plus documented plant change and rollback procedure
- Access to current Rockwell product documentation for the exact catalog and firmware revision
4. Step-by-Step Engineering Workflow
- Step 1: Define the data contract and ownership
- Step 2: Create matching data structure where appropriate
- Step 3: Configure the producer tag
- Step 4: Configure the consumer path/tag
- Step 5: Verify data updates online
- Step 6: Test producer/controller/network loss
- Step 7: Document recovery and structure revision procedure
The sequence is intentionally layered so network, I/O, program and visualization faults are not mixed together. Record the as-tested state after every major commissioning stage.
5. Programming / Configuration Best Practices
Publish a stable UDT/interface instead of unrelated individual tags
Assign one clear producer for each command/status item
Document requested update/connection expectations
Use connection health in permissive and stale-data handling
Version the shared structure carefully to protect both controllers
6. Practical Example
The following copy-ready pattern demonstrates the core engineering idea. Adapt tag names and device/profile members to the tested project revision.
// Example shared interface structure usage
Line2_StartRequest := From_Line1.Start_Request AND From_Line1.Interface_Valid;
To_Line1.Line2_Ready := Line2_AutoReady;
To_Line1.Line2_Running := Line2_Running;
To_Line1.Line2_Faulted := Any_Line2_Fault;Use the example as an engineering pattern. Exact profile members, instruction options and supported features depend on the selected hardware/firmware/software revision.
7. Commissioning and Validation Checklist
- Verify the correct controller/server/device identity.
- Save a baseline project/application backup.
- Test one signal or equipment object end-to-end before copying the pattern.
- Test communication loss, field fault, permissive loss and reset/recovery behavior.
- Review forces, bypasses, temporary tags and security changes.
- Archive final backup, IP/device list and acceptance evidence.
8. Troubleshooting Matrix
| Symptom | Likely Area | Engineering Check |
|---|---|---|
| Consumed data does not update | Controller path / tag definition | Verify producer route, tag name/type and connection state |
| Controller accepts stale command after network loss | Application validation | Add communication/interface-valid conditions before acting on remote commands |
| Connection breaks after UDT edit | Interface structure change | Coordinate structure revisions and verify producer/consumer definitions on both sides |
| Two PLCs issue conflicting commands | Ownership design | Define command authority and handshake state explicitly |
| Data updates but sequence races | Handshake design | Use request/acknowledge/state semantics rather than assuming simultaneous scans |
9. Industrial Applications
This topic carries commercial intent because the same skill is used in training, breakdown support, retrofit, migration and new-project commissioning.
- Line-to-line handshakes
- PLC redundancy of information between cells
- Material transfer coordination
- Packaging line synchronization
- Plant interlock data exchange
10. Complete Hands-On Lab
Use a training rack, simulation system or approved offline test environment. Do not force outputs or inject faults on live equipment without the plant safety/change procedure.
- Create a safe lab project for two supported Logix controllers connected over EtherNet/IP with a defined inter-controller data structure
- Document the objective: create a documented PLC-to-PLC interface that fails predictably when the producer or network is unavailable
- Define the data contract and ownership
- Create matching data structure where appropriate
- Configure the producer tag
- Configure the consumer path/tag
- Introduce one controlled fault and capture diagnostic evidence
- Verify recovery, save the final backup and complete a one-page commissioning record
Save the final project, network/I/O map, fault evidence and commissioning checklist. This gives the learner a portfolio-quality industrial exercise and gives corporate teams a reusable troubleshooting standard.
11. Training and Project Support
This topic is linked directly to Rockwell PLC, VFD & SCADA Training and Rockwell Corporate Training. Training can be aligned to installed ControlLogix/CompactLogix hardware, 1734/5069 remote I/O, PowerFlex drives, EtherNet/IP and FactoryTalk View SE.
Project enquiries can use the same workflow for integration, breakdown support, SLC/PLC-5 modernization, SCADA upgrades, network troubleshooting and FAT/SAT commissioning.
12. Frequently Asked Questions
What is the main advantage of produced/consumed tags?
They provide a native Logix controller data-sharing mechanism with a defined connection, useful for structured PLC-to-PLC interfaces.
Should commands be accepted directly from consumed data?
Use explicit interface-valid, mode and permissive logic so a remote value cannot bypass the local ownership and safety design.
Can I change a shared UDT casually?
Treat interface structure changes as controlled revisions because both producer and consumer projects may need coordinated updates.
For version-specific engineering, verify the current Studio 5000 Logix Designer, ControlLogix/CompactLogix, PowerFlex and FactoryTalk View Site Edition documentation from Rockwell Automation.
Studio 5000 Logix Designer · FactoryTalk View Site Edition Help