You do not need a vendor panel, a per-seat design suite, or the hardware on your desk. Here is the full workflow: device → tags → drag-and-drop screen → alarms → live test, using a simulator until the real equipment shows up.
Traditional HMI development chains you to a vendor: screens built in their design suite run only on their panels, licensed per device, updated by walking a USB stick to each machine. That is defensible for a single machine builder shipping identical panels. It is painful for everyone else — integrators juggling five vendor tools, plants mixing equipment generations, and engineers who just need a working screen this week.
The modern alternative is a SCADA with a built-in drag-and-drop HMI designer: screens live on a server (or a Windows app), talk to any Modbus/OPC UA/MQTT device, and display anywhere — including in a plain browser. Below is the exact workflow, and none of it requires physical hardware to start.
In Device Manager, add your PLC or meter: protocol (Modbus TCP or RTU), host/COM port, unit ID — then hit Test Connection to confirm the link before saving. No hardware yet? Run a Modbus slave simulator on the same PC and connect to 127.0.0.1. The rest of the workflow is identical, which is exactly the point: your screens will not care when you swap the simulator for the real device.
Tags turn raw registers into named signals: TANK_LEVEL = holding register 40001, scaled 0–100%, unit %. Set the data type carefully (uint16 vs float32 across two registers is the classic mistake — see our register types guide) and add scaling so the HMI shows engineering units, not raw counts.
Drag widgets from the palette onto the canvas: gauges for pressures, tanks for levels, pumps and valves for equipment state, buttons for commands, trends for history. Bind each widget to a tag, set min/max ranges, and keep the design rules in mind — muted colors for normal, red and amber reserved for alarms. Group related equipment, align to the grid, and put the overview first.
Configure limit alarms on the tags that matter: high-high pressure, low tank level, motor fault bits. Give each a priority and a message an operator can act on. The alarm banner, viewer and history come with the SCADA — no extra wiring on the screen.
Switch the designer to run mode. Values move, colors change, buttons write to the device. Now rehearse the bad day: use the simulator to push values past alarm limits, drop the connection, restart the device — and watch whether the screen tells the truth clearly. This rehearsal is the single highest-value hour in HMI development.
Screens run on the server or the desktop app; adding a viewing station is a browser, not a purchase order.
Modbus TCP, RTU, OPC UA and MQTT devices on the same screen — regardless of equipment vendor.
Save the screen and every station has it. No project downloads, no USB sticks, no version drift between panels.
Because the data source is just Modbus, a simulator stands in for the plant. Screens are commissioned before commissioning.
Every tag can be historized and trended without a separate historian package.
Vendor panels can keep running local control while the new screens take over supervision — no rip-and-replace.
Yes — SCADA Desktop has a 30-day free trial (then $199 perpetual), and SCADA Cloud is free for 30 days with no credit card. The Modbus simulator used for testing has a free trial as well.
If the panel has a browser (most modern ones do), it can display the web version of your screens in kiosk mode — see our web-based HMI guide. Native vendor-panel runtimes remain vendor-locked; that is precisely what this workflow avoids.
Yes. Buttons and sliders write to coils and registers with role-based permissions (viewers cannot write), and every write is auditable.
Edit the device entry: change 127.0.0.1 to the PLC's IP (or select the COM port for RTU), run Test Connection, save. Tags and screens stay untouched.
Drag-and-drop HMI designer, Modbus TCP/RTU, alarms, trends and a simulator to test against — on Windows or in the browser. No vendor lock-in, no per-panel licenses.