The SMH2G(i) does not accept keyboard scan codes over its serial port as simulated local keypresses. This limitation also applies to the SMH2G variant discussed in the available evidence.
Supported Input Behavior
SMArt processes physical keyboard input, but no supported path connects serial data or a Modbus input register to the keyboard polling service. Writing a key scan code to the controller therefore cannot trigger the same action as pressing its local keyboard.
| Requested function | Evidence-based status |
|---|---|
| Inject SMH2G(i) keypresses through the serial port | Not available |
| Add the function only to SMH2G | Still requires rebuilding the operating system |
| Use existing SMH2010 input methods | Identified as an available alternative |
Why a Modbus-to-Keyboard Mapping Is Not a Configuration Change
The proposed design would read an incoming Modbus register, validate the value, and pass it to the keyboard polling service. The evidence indicates that this path does not exist in the current system and cannot be added through normal application configuration.
Implementing it would require a complete operating-system rebuild. The same constraint applies to SMH2G. The proposed implementation would also dedicate the affected port to keyboard input, making it unavailable for other serial functions.
Engineering Decision for Enclosed Installations
For an installation where the controller keyboard cannot be pressed directly, do not base the design on serial scan-code injection. Select an existing SMH2010 input method or redesign the operator-input interface around functions the controller already exposes.
If custom firmware is being considered, first confirm that the operating system can be rebuilt for the target controller and accept that the selected port may become keyboard-only. Treat the feature as a platform modification requiring vendor involvement, not as a Modbus register-mapping task.
Verification Procedure
- Identify whether the target is SMH2G or SMH2G(i); neither model has the requested serial keyboard-emulation path in the available evidence.
- Confirm that the design does not reserve a serial or Modbus register for key scan codes on the assumption that SMArt will process them.
- Validate the selected existing input method on the target controller and verify that every required operator action can be completed without physical keyboard access.
FAQ
Can SMH2G(i) accept keyboard scan codes through its serial port?
No. The available implementation does not convert serial scan codes into SMArt keyboard events.
Can serial keyboard emulation be added only to SMH2G?
Not as a normal configuration change. The evidence states that SMH2G would also require an operating-system rebuild.
Would the serial port remain available after adding keyboard emulation?
The proposed operating-system modification would make the port dedicated to the keyboard function and unsuitable for other serial uses.