Change an HMI panel IP address from its own screen

Can an operator change the panel's IP address from its own screen?

Yes, on the panel family this procedure is documented for. Hold the upper-left corner of the touch screen for 10 seconds, confirm the prompt, open Settings, and the IP address, subnet mask and gateway can all be entered at the panel with no programming software.

Panel makers expect addresses to change. Cells move, lines get renumbered, and the maintenance tech standing at the machine is the person who has to fix it. These panels carry built-in system setup screens for exactly that job. The manual lists the IP address among the settings that can be written at the panel as well as from the programming software or by the project. The on-screen route is a documented path, so nothing here is a workaround.

Finding an address a panel already has is a different job. The writeup on setting the subnet mask and gateway when the panel shows only an IP covers that discovery side. This article is about writing an approved new value.

Which values do you need before you change anything?

Three values come from the network plan: the approved IP address for the panel on that segment, the subnet mask, and the gateway. The plan lists a gateway only when the panel must reach devices outside its own subnet. Write the panel's current values down first so they can be restored.

The plan lives with whoever owns the plant network: the controls drawing, a panel schedule, or the group that assigned the line its addresses. Read the panel's current three values from the same dialog you are about to edit and write them down. The fastest recovery from a mistake is retyping the values that worked before.

Before you assign the new address, ping it from a laptop and wait 5 seconds. A reply means another device already holds it. Setting it anyway drops communication for both devices until one of them is moved. A mask that disagrees with the plan is just as costly: it hides devices that should be local.

One working rule for the job itself: if this panel is the cell's only window into the machine, make the change during a planned stop. That way the seconds the link is down never overlap a running cycle.

How do you open the hidden IP settings dialog on the panel?

Hold the upper-left corner of the running screen for a full 10 seconds, answer Yes to the prompt, select Settings, and hold the upper-left corner again. The second hold is the step people miss, and without it the dialog never appears.

1. Touch and hold the upper-left corner of the running screen for the full 10 seconds. A short hold is the usual reason nothing happens.
2. Select Yes on the confirmation prompt.
3. Select Settings.
4. Hold the upper-left corner again until the IP address setting dialog appears.

If the dialog does not appear, the likely miss is a short first hold. Count the 10 seconds out properly, answer the prompt, and repeat the corner hold inside Settings. Do not type addresses into another numeric field that happens to open. The screen you want is the one the panel shows as the IP address setting dialog, and any other field you fill is a different setting.

Panel families hide this screen in different places. The sequence above is the documented one for the family this procedure comes from. On another family, the System Setup chapter of its manual prints the path, and some families open their setup screens from a boot menu instead of a touch hold.

How do you enter the new IP address, subnet mask and gateway?

Work down the dialog in the order the panel expects. Pick the IP address setting, key the approved address on the numerical keypad, press ENT, and repeat value-then-ENT for the subnet mask and for the gateway when the plan calls for one.

1. Select the IP address setting. The dialog marks it with a radio button and opens a numerical keypad.
2. Key in the approved address and press ENT.
3. Key in the approved subnet mask and press ENT.
4. Key in the approved gateway and press ENT, when the plan lists one.
5. Read all three values back on the screen before leaving the dialog. A transposed digit caught here takes 10 seconds to fix; caught at startup it stops the line.

The gateway line deserves its own decision. A gateway is used only when the panel must send packets to a device outside its own subnet. On a single-switch line where the panel and PLC share the same subnet, the plan often leaves it blank. Enter whatever the plan prints for this panel, and do not copy a gateway from an unrelated device. A gateway from another segment will not serve this one.

Example: a panel moved onto a 192.168.1.x line

A panel moves from a scrapped cell to a live line. The plan gives it 192.168.1.57 with subnet mask 255.255.255.0 and gateway 192.168.1.1. The PLC it must reach sits at 192.168.1.10, so panel, PLC and laptop all share one 192.168.1.x subnet.

1. On the laptop, ping 192.168.1.57 and wait 5 seconds. No reply means the address is free.
2. At the panel, open the dialog, key 192.168.1.57 and press ENT, key 255.255.255.0 and press ENT, then key 192.168.1.1 and press ENT.
3. Check the arithmetic. With mask 255.255.255.0, two devices talk directly when their first three number groups match. Panel 192.168.1.57 against PLC 192.168.1.10 gives 192 = 192, 168 = 168, 1 = 1, and only the last group differs (57 against 10). A switch carries the traffic, and the gateway at 192.168.1.1 is never crossed.
4. Result: the laptop's ping to 192.168.1.57 replies within 1 second, and the panel's live PLC values start moving again.

The contrast case shows what moves the decision. Key 192.168.2.57 by mistake and the third group becomes 2 against the PLC's 1. The panel now sees the PLC as off-subnet and hands every packet to a gateway. On a flat line with no router between 192.168.1.x and 192.168.2.x, nothing answers. The symptom is a panel whose screen looks healthy while no data moves.

How do you verify the link to the PLC after the change?

Verify in two steps. From a laptop on the same network, ping the panel's new address and expect a reply within 1 second. Then watch a heartbeat counter, a PLC register that increments every scan, and confirm it keeps moving for at least 30 seconds.

The ping proves the panel is reachable. A ping reply alone does not prove the application link is healthy, so open a panel screen bound to live PLC values and watch them change with the machine. The heartbeat method, including which register to use and how to alarm on it, is written up in verify HMI communications with a PLC heartbeat counter.

If the panel writes setpoints or acknowledgements into the PLC, run the write test before anyone presses start. That test is set out in operator panel PLC link setup: test writes before motion.

What if the panel still will not communicate?

Work outward from the change. Re-read the three values on the panel against the plan digit by digit, ping the panel from the laptop, ping the PLC's own address, and only then look at cables and switch ports. Each step either passes or points at one side of the link.

• No reply when you ping the panel's new address. Re-check the three values digit by digit; a transposed digit is the most common cause. Confirm the laptop itself sits in the same subnet for the test.
• A reply to the ping even with the panel's cable pulled. Another device holds the address. Leave the panel unplugged, ping again, and if it still answers, take the conflict to the network owner.
• The ping works but the PLC values on the screen stay frozen. Reachability is fine, so the fault sits in the panel's driver settings or the PLC's Ethernet service. When one link is up and the other is down, a dead programming link while the PLC link still works helps tell the two apart.

Resist the urge to re-enter guessed addresses. Each wrong entry risks colliding with a device that was talking fine before you started.

When should you stop and hand the job to the network owner?

Stop and ask in three cases: the approved values for the segment are not written down anywhere, a ping answers before you assign the address, or the dialog will not open after repeating the full two-hold sequence. Guessing an address can take two devices down at once.

Hand the network owner a short, complete request: the panel family and model, the three current values read from the screen, the address you are asking for, and the switch or VLAN the panel hangs on. That is enough for a same-day answer, and it avoids the back-and-forth that leaves a panel sitting dark on a cart.

Recommendation: change the address at the panel whenever the approved IP, subnet mask and gateway are written down in front of you and a ping to the new address stays silent. When either condition fails, get the plan first. When the dialog stays closed after a careful repeat of both holds, set the same values through the programming software or project path the manual documents.

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