Direct answer
In a web HMI project, the first hardware question is where the browser client runs. Choose a panel PC when the operator station must include the computer, operating system, browser, local files, updates and touch display in one configured unit. Choose an industrial touch monitor when a separate IPC or computer runs the browser and sends video to the screen. A PLC web server does not remove the need for a browser-capable client.
Where Does the Web-HMI Browser Actually Run?
A browser-based HMI normally separates three hardware and software roles:
- HMI Web Server: may run on a PLC, industrial server, IPC or controller.
- Browser Client: runs on a panel PC, IPC, industrial computer or another computing device capable of running the browser.
- Display / Touch Layer: may be integrated into the panel PC or provided by a separate industrial touch monitor connected to the browser client.
A PLC that hosts the HMI web server does not automatically replace the browser client. A standalone industrial touch monitor still requires a video-capable host that runs the browser and outputs the display signal.
The display and touch layer should be treated separately from the software host. A touch monitor can be the operator display, but it is not the browser computer by itself.
Three Common Web-HMI Hardware Architectures
Architecture A: PLC or Web-HMI Server to Panel PC
PLC / Web-HMI Server -> Ethernet -> Panel PC -> Local Browser + Touch Display
This fits projects where the panel PC is the browser client and local operator station. The panel PC selection should cover mounting, software image ownership, update method, service access and touch/display integration.
Architecture B: PLC or Web-HMI Server to External IPC to Touch Monitor
PLC / Web-HMI Server -> Ethernet -> External IPC / Browser Client -> HDMI / DP -> Industrial Touch Monitor, with USB Touch back.
This fits projects where another host runs the browser and the touch monitor is display and input hardware. Video and touch interfaces must be reviewed separately before sampling.
Architecture C: Existing Machine Host to Replacement Display
Existing IPC or embedded host -> Video output -> Industrial touch monitor, with touch returned to the host.
This can work when the software host already exists and the project mainly needs a different size, mounting structure or touch/display replacement.
Architecture Decision Table
| Decision point | Panel PC direction | Industrial touch monitor direction |
|---|---|---|
| Browser client location | The operator station runs the browser locally. | A separate IPC, computer or embedded host runs the browser. |
| Display signal | Internal display path is part of the configured unit. | External video from the host must match the monitor input. |
| Touch path | Touch controller is integrated into the panel PC configuration. | Touch returns to the host through USB or another selected touch interface. |
| Service model | Computing, display and touch are serviced as one configured station. | Display/touch can be serviced separately from the browser host if interfaces match. |
| Machine safety | Emergency-stop and enabling-switch functions remain part of the final machine safety architecture and compliance assessment. | |
When You May Not Need a Panel PC
You may not need a panel PC when an existing IPC, embedded computer or controller-side host already runs the Web-HMI browser and the display location only needs video plus touch. In that case, review an open frame touch screen monitor or another industrial monitor format instead of moving the software host into the operator panel.
A touch monitor path still needs checks for active area, front-frame clearance, cable exit, grounding, water accumulation risk, FPC route and host touch recognition.
Browser and Operating System Considerations
Browser and operating system requirements should be written as project inputs. Avoid assuming that every panel PC configuration supports every web runtime, update policy, kiosk mode, driver package or security setting. The selected configuration should be reviewed with the software owner before sample approval.
Web-HMI Hardware Selection Checklist
- Identify where the Web-HMI server runs and where the browser client runs.
- Separate the video interface from the touch interface in the RFQ.
- Confirm host output, monitor input, touch controller communication and driver expectations.
- Review LCD board, touch controller and metal frame grounding as a system.
- Keep the sensor active area clear of conductive frame edges and front-bezel interference.
- Plan FPC and USB cable routing away from high-frequency signals and host power paths.
- Run Sensor Test after host or mainboard changes and retune the whole system before repeat production.
Related engineering resources
Source and evidence boundary
This article is based on EverGlory installation and engineering-control material covering TP/LCD integration, controller and LCD board grounding, FPC routing, sensor active-area clearance, Sensor Test after host changes, wet-touch risk and whole-system tuning before production. It does not claim a default computing configuration, browser release, safety approval, environmental rating or lifecycle period.
This guide does not turn a project requirement, interface name or component capability into a universal product claim. Certification, protection rating, environmental limits, lifecycle and availability must be confirmed against the selected configuration and evidence package.
Frequently asked questions
Is Web HMI the same as a panel PC?
No. Web HMI describes how the operator interface is delivered, usually through a browser or web runtime. A panel PC is one possible browser-client hardware choice.
Can a touch monitor run a Web HMI by itself?
No. A touch monitor normally provides display output and touch input. The web application must run on a connected host, such as an IPC, panel PC or other browser-capable computer.
Can a PLC web server connect directly to a touch monitor?
Not as a complete operator station. If the PLC only hosts the web server, a browser-capable client still has to render the interface and output the video signal.
When is a panel PC the better Web-HMI choice?
A panel PC fits when the machine builder wants the browser client, operating system, update control and touch display inside one operator station.
When is a touch monitor enough?
A touch monitor may be enough when the HMI software already runs on another host and the project mainly needs a suitable display, touch interface and mounting format.
Can emergency-stop or enabling-switch functions be assumed from HMI hardware?
No. Those functions are part of the final machine safety architecture and compliance assessment. They should be specified and validated by the machine builder or system integrator.
Send the Web-HMI hardware architecture
Share where the HMI server runs, where the browser client runs, the target display size, video signal, touch interface, mounting structure, host system and safety-control boundaries. EverGlory can review whether a panel PC or touch monitor path fits the project.
