Limit the HMI web server screen list to a few screens

What you need

• A network path from your PC to the panel: the plant LAN, or a VPN tunnel from outside.
• An FTP client. FTP's control connection uses TCP port 21, the port the IANA assigns to the protocol, so the client already aims there.
• The panel's web page open in a browser, to compare before and after.
• The FTP server enabled in the installed project. If it is off, no FTP client can log in; that is a project setting, and the fix is reinstalling the project with it on.
• A folder for untouched copies of every HTML file, saved before you change anything.

Why the USB stick cannot carry the page edit

The obvious plan for a panel far from the office is to prepare everything on a bench panel, write it to a USB stick and mail the stick. That plan deploys a whole panel and fails for one page, and the difference is in what the image holds. In the project software, the Send Project command with the Load to External Memory Device option writes one image containing three things: the project, the OS and the firmware. There are no HTML files in it. Restoring that image asks you to select System and Project, and with both selected the restore updates the target panel's OS and firmware along with the project.

Treat the image as a whole-panel deployment tool. Use it when the target should take a new project and new system software together; before such a restore, check the panel's firmware revision before a project transfer so you know what arrives with the project. Do not spend a firmware restore on a link list: a panel running a line takes its firmware change in a planned stop, with the project backed up first.

Cut the list to the screens you need

1. Open the panel's web address in a browser and note what the landing page lists now, link by link. This is your before picture and your test list.
2. Connect the FTP client to the panel's IP address on TCP port 21. If it refuses or times out, work through Connect an FTP client to an HMI panel over Ethernet before touching any file.
3. Download every HTML file on the panel into the originals folder and leave that folder alone. Those files are the rollback for this job.
4. Find the entry page. Its name is index.htm or default.htm, and the panel serves one of the two. Compare each file against the page your browser shows and edit the one that matches.
5. Edit that page in a plain text editor. Delete the link rows for every screen remote users should not see, and keep the surviving screen references exactly as the page writes them. To go further, copy the page as a template and build your own links on it; the files are ordinary HTML.
6. Copy the edited page back to the panel with the FTP client.
7. Reload the landing page and click each link you kept.

Example: three screens on a panel 1,200 miles away

Inputs, and where each comes from:

• Screens the remote users need: 3 screens. The requirement that starts this job.
• Links on the landing page before the edit: 12 links. An example input, so the arithmetic has something to chew on; read the real count off your own landing page in step 1.
• Distance to the panel: 1,200 miles, nobody on site. A typical remote plant.
• Files to change: 1 entry page, named index.htm or default.htm. 2 possible names, from the panel's file set.
• What a Load to External Memory Device image carries: 3 components, the project, the OS and the firmware. HTML files carried: 0 files.
• FTP control port: TCP port 21, the IANA assignment for FTP.

The rule in words: an HTML edit reaches the panel only through FTP. The USB image carries no HTML files, so it cannot deliver the edit. FTP works only when two conditions hold: the installed project has the FTP server on, and TCP port 21 reaches the panel.

The arithmetic: files you must change, 1. Files the image can deliver, 0. 1 - 0 = 1 file short, and that file travels only by FTP. Links trimmed, 12 - 3 = 9 links deleted. Conditions FTP needs, 2. The job is therefore 1 FTP session with 2 conditions met: download both candidate entry pages, trim the list down to 3 links, copy 1 page back.

The result: one session at a desk finishes the edit. No stick, no courier, no firmware touched.

The decision: if the installed project has FTP on and port 21 reaches the panel, do the whole job remotely and keep the 1,200 miles out of it. If FTP is off, one session with someone at the panel comes first, because no number of USB sticks changes the count: the image still carries 0 HTML files.

Recommendation: if the installed project has its FTP server turned on and TCP port 21 reaches the panel, trim the list from your desk in one session: save the originals, edit the entry page down to the 3 screens remote users need, copy it back, then test a removed screen's address as well as the kept links. If FTP is off, book the one project-transfer session that turns it on before promising anyone a shorter page; the USB image cannot bring the edit with it.

If the FTP server is off in the installed project

An FTP client that cannot log in, while the panel pings and serves its web page, points at the project setting. Open the project, turn the FTP server on and transfer it with the normal project workflow; the panel then accepts FTP with no hardware change. Reachability and FTP availability are two separate checks, and a client retry cannot switch the server on from outside. Plan that one transfer session, then run the edit as in the example above.

How to check it worked

• The landing page lists exactly the screens you kept, and each link opens. If a page opens with zeros where numbers belong, the tag paths are the fault; Why an HMI web server shows zeros for PLC tags walks that one.
• Open a removed screen by its own address. It still loads: cutting a link changes the menu, not the permission. If remote users must be kept out of screens, set the panel's password and screen security in the project and test it from the web side.
• If the page looks wrong after the copy, put the saved original back by FTP and retest. The rollback for a page edit is the original file, never a system restore.
• If the web page stops answering mid-job while FTP still moves files, that split has its own cause; HMI panel web server stops responding but FTP still works covers it.
• Run the session from the plant network or over a VPN; FTP sends the password in clear text across the open internet. View a plant HMI web page from home over VPN sets up the tunnel.

A wall board instead of more web access

If the reason for limiting the web list is that the line wants its numbers in view, a dedicated screen at the station often serves better than panel logins. Show a web OEE dashboard on a factory TV screen covers the playback path, and we build shop-floor signage for exactly that spot. Keep the HMI panel as the control surface and the board as the display.

Questions