The workstation can build control logic, but communication with the controller fails, the selected target appears unreachable, or an online operation reaches the wrong device. Follow the packet from Proficy Logic Developer Machine Edition through the workstation interface, physical network or programming cable, communications configuration, and controller endpoint. Check layer one before changing ladder logic or rebuilding the project.
Where does the communication path stop?
The request originates in the development environment and must cross every configured and physical hop before a 90/30, 90/70, VersaMax, RX7i, or RX3i controller can answer. A failure at any earlier hop prevents higher-level diagnostics from proving anything.
| Path segment | Reading or observation | Pass result | Failure meaning |
|---|---|---|---|
| Workstation | Interface state and local connection | The intended interface is active | Operating-system, adapter, or cable problem |
| Physical link | Link indication, connector seating, cable condition | Stable connection at both ends | Layer-one failure; stop protocol testing |
| Configured route | Selected interface and destination | Route matches the installed path | The request leaves through the wrong adapter or toward the wrong endpoint |
| Controller | Power, run-state indication, and communications status | Controller and communications hardware are operational | Controller-side hardware, power, or configuration fault |
If the physical link is absent, repair that branch first. If the link is present but the destination does not answer, proceed to addressing and route selection. If communications work but the project cannot perform the intended online operation, compare the configured controller family with the installed hardware.
Is the physical layer carrying the request?
Inspect the complete path, not only the workstation connector. Verify controller power, interface seating, cable retention, connector damage, and any intermediate networking equipment. A link indicator proves electrical link establishment; it does not prove that the application is using the correct route or that the controller accepts the request.
For a direct programming connection, confirm that no unrecorded adapter or converter changes the interface presented to the software. For a networked connection, identify the workstation adapter actually connected to the control network. Multiple enabled adapters can create a valid physical link while the request follows a different operating-system route.
- Record the intended workstation interface and controller endpoint.
- Disconnect and reseat only the connectors in that documented path.
- Observe whether the link state changes at both endpoints.
- If link remains absent, substitute one physical component at a time and repeat the observation.
- Continue to protocol checks only after the physical state is stable.
Does the configured address match the endpoint?
Compare the project communications settings with the installed path. Read values from the controller configuration, workstation interface, and project rather than relying on labels or an old project copy. The address form depends on the selected communications method, so use the fields presented by that interface and do not transfer assumptions from a different connection type.
| Setting | Compare against | If matched | If different |
|---|---|---|---|
| Selected workstation interface | Physical adapter or programming interface in use | Test the destination | Select the interface carrying the actual connection |
| Destination address | Controller or communications-module configuration | Check reachability | Correct the project route or the documented device configuration |
| Port or channel | Installed connection point and its configured mode | Check protocol compatibility | Use the port configured for the programming path |
| Timing setting | Path latency and interface configuration | Retest consistently | Correct the path before extending timeouts |
| Controller family | Installed hardware identification | Proceed to target validation | Correct the project target before an online operation |
A longer timeout cannot repair a wrong address, wrong interface, or disconnected cable. If the destination is reachable outside the development environment but not from the project, focus on the selected route and project communications configuration.
Does the project target match the installed controller?
Proficy Logic Developer Machine Edition supports control development for the listed 90/30, 90/70, VersaMax, RX7i, and RX3i families. The project target must represent the controller being contacted. A physical reply establishes communication only; it does not establish that the project hardware definition and controller application are compatible.
Read the controller family and hardware identity from the installed equipment, then compare them with the target definition. Check the configured rack, modules, and communications hardware against the physical assembly. Resolve mismatches before transferring control logic. Ladder logic may be syntactically valid while addressing hardware that is absent or configured differently.
If the family matches but the online comparison reports differences, determine whether they are expected application changes or an incorrect project revision. Preserve the running configuration before replacing controller content. Do not treat successful discovery as authorization to download.
Can the software complete an online operation?
Test progressively. A staged test identifies the first failing transaction and avoids combining route, target, and application problems into one symptom.
- Open the intended project and select the target representing the installed controller family.
- Select the workstation interface connected to the controller path.
- Enter or select the destination using values read from the installed configuration.
- Initiate a non-transfer online connection or device-identification operation.
- Confirm that the returned controller identity matches the intended asset.
- Compare the online controller configuration and application with the project.
- Resolve family, module, and project-revision differences before any transfer.
- Perform the required online operation and watch for a communications interruption or configuration rejection.
If identification fails, return to the physical route and address branches. If identification succeeds but comparison fails, investigate project-to-controller compatibility. If comparison succeeds but a transfer fails, capture the exact operation, stage, and diagnostic text shown by the development environment.
How do you verify the resolving branch?
Verification must prove the route, identity, project match, and control behavior independently. Repeating only the operation that originally failed can hide an intermittent physical fault or a connection to the wrong controller.
| Verification | Required observation | Failure branch |
|---|---|---|
| Physical stability | Link remains stable while the cable and intermediate equipment remain undisturbed | Inspect or substitute physical components |
| Endpoint identity | Returned hardware identity matches the intended controller | Correct the destination or route |
| Project comparison | Differences are understood and approved | Correct the target or project revision |
| Online monitoring | Ladder states and referenced I/O correspond to controlled test conditions | Check application addressing and hardware configuration |
| Reconnect test | A fresh session reaches the same controller through the documented path | Recheck interface selection and route persistence |
Record the working interface, destination, controller family, physical connection point, and project revision. Close the session, reconnect through the recorded path, identify the controller again, and confirm that online ladder states follow a controlled input or operating-state change.
FAQ
How do I connect Proficy Logic Developer Machine Edition to a PLC?
Verify the physical link, select the workstation interface carrying that link, configure the destination from the installed controller settings, and perform a non-transfer identification operation before comparing or transferring logic.
How do I troubleshoot a PLC that appears unreachable?
Start with controller power, connectors, cable condition, and link state. If layer one passes, compare the selected interface, destination address, port or channel, and route with the installed configuration.
How do I verify that I selected the correct controller target?
Compare the installed controller family with the project target; supported families listed here are 90/30, 90/70, VersaMax, RX7i, and RX3i. Reconnect, identify the endpoint, and confirm that monitored ladder states respond to a controlled operating-state change.