An SMH4 controller installed inside a cabinet cannot expose its built-in temperature-curve editor conveniently to an external Weintek operator panel when the protected macro does not process its button inputs. The evidence supports two practical paths: display the SMH4 interface through VNC, or replace/adapt the graph macro with one whose editing actions are exposed through buttons. VNC was proven to connect and operate, but it did not produce an acceptable interface on the 10-inch panel.
Confirmed mechanism and constraints
| Item | Confirmed result | Engineering consequence |
|---|---|---|
| SMH4 installation | The controller is mounted inside the cabinet. | Operators need graph access from an external HMI or SCADA interface. |
| Existing temperature-graph macro | Its button inputs are not used internally, and the macro is password-protected. | The Weintek panel cannot edit the graph merely by writing to those unused inputs. |
| Weintek VNC viewer | It connected to the controller and worked. | Remote operation is technically possible without modifying the protected macro. |
| 10-inch display result | The controller image was difficult or potentially impossible to stretch acceptably; image quality was considered poor. | VNC did not meet the presentation requirement despite successful communication. |
| Matrix graph alternative | A graph macro with button-based operation was identified. | It may provide editable controls, but adaptation for SMH4 requires recalculation and image changes. |
Choose the external-editing architecture
Use VNC when reproducing the SMH4 screen is acceptable and no native 10-inch layout is required. Use an editable replacement or adapted graph macro when operators need a clean Weintek interface, individual curve-point control, or an interface designed for the panel resolution. Do not base the design on the existing macro button inputs unless testing confirms that its internal logic actually consumes them.
A whole-curve offset is a separate decision. It moves the curve as one unit and can be suitable when commissioning requires only a uniform correction. It cannot independently reshape individual regions of the curve. The evidence also identifies a potentially confusing connection: the graph macro input labeled as an offset was connected internally to an input labeled for a domestic-hot-water setpoint. Because the protected implementation cannot be inspected, treat the meaning of that connection as unresolved and verify it experimentally before exposing it to operators.
Commission the VNC option
- Configure the Weintek project to open the SMH4 display through its VNC viewer.
- Confirm that the panel connects and that operator actions reach the controller.
- Evaluate the complete operator workflow on the actual 10-inch panel rather than accepting connectivity as the completion criterion.
- Check image scaling, available display area, legibility, touch targeting, and whether a special surrounding Weintek project is needed to make the result presentable.
- Reject the VNC approach if the controller image cannot be stretched or positioned with acceptable quality.
This test separates communication success from interface acceptance. In the documented case, the connection and controls worked, but scaling and visual quality caused the design to be abandoned.
Implement native curve editing
- Define whether the operator needs a whole-curve offset or independent point editing. Do not expose more authority than the operating requirement demands.
- If point editing is required, evaluate the Matrix-derived graph because its operations are driven by buttons.
- Adapt the graph for SMH4 by recalculating its layout and replacing or resizing its images as required. The evidence does not establish that an unchanged Matrix graph fills the SMH4 screen.
- Map the external HMI controls only to variables or button actions that the selected macro demonstrably processes.
- Keep any existing internal and external offsets from acting twice. The reported implementation already had offset behavior in two places, so verify the final signal path before commissioning.
The available evidence does not identify variable addresses, protocols, macro identifiers, or a supported method for removing the existing password. Those details must come from the actual project files and product documentation.
Verify commissioning behavior
Record the original curve before permitting edits. Exercise each exposed button or setpoint and confirm that only the intended point or offset changes. Test several outdoor-temperature regions because a source-temperature schedule can contain cutoffs where one supply temperature corresponds to multiple return-temperature conditions; supply temperature alone may therefore be insufficient to select the intended operating point.
For a building heating curve, compare the commanded internal-system temperature with observed building and return-temperature behavior during commissioning. The evidence supports adjusting the internal curve under different outdoor conditions during the first operating year, but it does not define adjustment values or intervals. Preserve the approved starting curve and document every accepted change.
FAQ
Can a Weintek panel edit the SMH4 temperature curve through VNC?
Yes, the documented setup connected and operated successfully. It was rejected because the SMH4 image did not scale cleanly on the 10-inch panel and the resulting presentation quality was unacceptable.
Why do the SMH4 temperature-graph macro button inputs not work?
The existing protected macro did not use those inputs internally. Writing to them from the external HMI therefore cannot edit the curve unless the macro implementation is replaced or changed.
Should operators edit curve points or use one temperature offset?
Use an offset when the entire curve needs the same correction. Use exposed point controls when commissioning requires reshaping only part of the curve; verify that internal and external offsets are not both applied.