I am working with the VC Project “Keys” interface through VNC and facing an input issue:
The alphanumeric keys work fine for string inputs.
The numeric keypad keys do not respond when numeric inputs are required.
The navigation buttons (up, down, left, right) also do not work in VNC.
On the physical hardware, both numeric and navigation inputs work correctly.
Other keys like SEL, OK, ESC, and function keys responds sometime as expected.
Setup details:
PLC: XEPIMC200.02
HMI: 4EPIMC30.104P-30K
For VNC, I have configured hotspots above the images. The red highlighted boxes work fine, and the alphapad characters are working. Only numeric inputs and navigation keys not working.
Has anyone experienced this issue? Any suggestions on fixing keypad and navigation input in VNC would be very helpful.
When you say everything is working correctly on physical hardware, do you mean that you have VC Keys mapped to physical hardware buttons? Or do you have this HMI running on physical hardware as well? It looks very much like a physical button panel and I can’t tell if your simulation is mimicking a physical panel or if you use the same visualization in both places.
When troubleshooting VC4 keys, my first recommendation is to double check that you have the correct key mapped to the button, and that each key is doing the expected action. If you have two different keys (one for the simulated HMI and one for a physical button panel), make sure that those actions are the same. Since both Local and Global key actions can be created, it’s possible to accidently override what was already there.
Additionally, do you have multiple layers within your visualization, or is it possible for anything to cover those buttons? Make sure that those buttons are on top of the layer and that you don’t have anything (e.g., an empty layer or a hotspot) covering them.
Finally, just a sanity check, but do you have any Status or Locking datapoints tied to those buttons? Is it possible they’ve been locked? They usually change color when this happens, but that is dependent on the styling used. If the entire button is a bitmap then you may not see a difference.
Setup clarification
VC keys are mapped to the hardware buttons, and for simulation I have created a separate VNC visualization with keypad buttons (using hotspots).
The same logical variables are used for both hardware and VNC interactions.
The physical buttons are working as expected, but in the VNC simulation specifically the numpad and navigation (scroll) keys are not behaving as required.
Verification of mappings and visualization setup
During troubleshooting, I verified that:
The same key actions and variables are used for both physical and VNC inputs
There is no overriding of key actions (Local/Global conflicts)
The visualization does not contain multiple overlapping layers, and no elements are covering the buttons
Hotspots are placed at the top layer
There are no locking or status datapoints bound to these elements
Observed behavior
When interacting via VNC:
Pressing numpad/scroll keys correctly updates the variable values in PLC logic
However, those updates are not reflected in the visualization (both hardware and simulation)
In contrast, when using physical keys, the same variables:
Update correctly
And the changes are properly reflected in the visualization
What actions are your keys performing (e.g., SetDatapoint, scrolling)?
I’m confused what you mean when you say that pressing the buttons updates variable values but that does not reflect in the visualization. Where are the values of the key presses going in your program, and how does that get transferred to the visualization?
I ended up talking through this with Ravi on Teams.
Ravi’s project, while running in sim, has two visualizations running on two different VNC ports. One is the main HMI and the other is a simulated keypad. The goal was to have a key press on the keypad (e.g., “4”) enter a character in an input box on the main HMI.
This is not natively possible as two different visualization instances do not share an input buffer. One possible workaround would be to write the value to a PLC variable which then gets sent to the visualization. However, Ravi solved this problem by creating a NumPad on the main HMI that pops up when an input box is touched. This is only an issue in simulation as on a real machine, the physical keys on the C30 are part of the same visualization as the rest of the HMI.
