Weintek HMI Buttons and Objects Disappear: Modbus Troubleshooting

5. Understand Local and Remote Device Settings

Do not change every Ethernet PLC to “Remote.”

In EasyBuilder Pro’s documented device architecture:

• A Local Device is connected to the local HMI.
• A Remote Device is connected through another HMI.

Therefore, “Local” does not mean that the PLC address is merely internal HMI memory. An Ethernet-connected device can belong to the local HMI’s device configuration.

The manual explains these distinctions in its local- and remote-device setup sections. Follow the actual communication topology and the selected driver’s instructions. Weintek EasyBuilder Pro V6.10.01, Chapter 5, sections 5.2.2–5.2.3

After a project conversion or device change, confirm that the affected objects reference the intended device entry. Correct settings on one device entry will not repair objects still pointing to another.

6. Check Interlocks and Visibility When Reads Are Valid

If the required values are readable, inspect the object’s display conditions.

For example, the EasyBuilder Pro manual documents Hide when disabled for a Set Word object’s interlock. When its configured condition is not satisfied, the object is hidden. Other object types have their own available security and visibility settings. Weintek EasyBuilder Pro V6.10.01, Chapter 13, page 13-22

Check:

• Whether hiding is enabled.
• Which value controls the condition.
• Whether that value is valid and current.
• Whether the comparison matches the intended machine state.
• Whether the current user has the required privileges.
• Whether the object’s appearance changes with its state.

A hidden object may be behaving exactly as designed. Confirm the intended behavior with the project owner before altering it.

Do not remove an interlock or privilege restriction to restore visibility on a running machine. Correct an identified configuration error through the approved change process.

7. Separate Connection Problems From Request Problems

If no relevant read succeeds, review the connection. If some reads succeed, prioritize the failing requests.

For Modbus TCP, check the destination IP, selected LAN interface, route, configured server port, and whether the intended Modbus service is available.

For Modbus RTU, compare the selected COM interface, station number, serial format, and cable pinout with the equipment documentation. Inspect or change wiring only under the applicable safe maintenance procedure.

For the broader connection workflow, see Weintek HMI “PLC No Response”: Serial and Ethernet Fixes.

Avoid treating a successful ping, a link light, or a general “connected” indication as proof that the missing object’s register is readable. Verify that specific transaction.

8. Investigate Background Requests Without Removing Production Functions

A communication warning can persist even when the displayed page looks normal.

Review background functions that reference the same device, such as alarm monitoring, data sampling, macros, and data transfers. Identify obsolete or incorrectly mapped addresses through diagnostics and project review.

Do not delete alarm or monitoring functions from the live application to silence a message. If isolation testing is necessary, perform it in a controlled project copy and preserve the original configuration.

Similarly, increasing a timeout is appropriate only when evidence shows that valid responses arrive too late. It does not repair an incorrect address or visibility condition.

9. Verify the Repair Before Returning to Normal Operation

Change one identified cause at a time, then compile and deploy through the normal maintenance process.

Confirm that:

1. The intended object appears under the correct conditions.
2. Its displayed state agrees with the actual device value.
3. Previously working objects still behave correctly.
4. Login and interlock behavior remain intentional.
5. Communication warnings no longer recur during the relevant operating sequence.
6. Any command function is tested only under an approved machine test procedure.

Where required, verify startup and communication-recovery behavior during a planned test. Restore diagnostic access settings according to site policy and save the corrected project.

If the problem remains unresolved, provide support with the project version, object configuration, server register map, and a captured failing request. These details are more useful than “the screen is blank.”