Resolving the SIMATIC KP400 Basic PN "Name Not DNA Compatible" IP Save Error

1. Problem Overview

Engineers commissioning a SIMATIC KP400 Basic color PN (MLFB 6AV6 647-0AJ11-3AX0) report that the panel refuses to accept an IP address entered directly through the on-device Settings > Network & Internet or Control Panel > IP Address dialog. The user enters a valid IP such as 192.168.0.2, presses Enter, and the panel returns a dialog titled "The name is not DNA Compatible. Only Lower letters are allowed...." The IP field is then not committed to the persistent configuration, and the device continues to use its prior (or factory) address. The dialog can be dismissed only with OK; no override exists.

This error is not an IP-subnet mismatch, not a DHCP failure, and not a hardware fault. It is a name-validation fault triggered because the PROFINET device name field on the same screen is empty or contains characters that violate the underlying DNS hostname rules of the PROFINET device model (IEC 61784-2). Siemens firmware prints the literal string "DNA" in some Basic Panel builds where the specification is "DNS-compatible"; treat the two as identical from a configuration standpoint.

2. Affected Hardware, Order Numbers, and Firmware Behavior

The error string appears across the second-generation SIMATIC Basic Panels (KP300, KP400, KTP400, KTP600, KTP700, KTP900, KTP1200) on PROFINET-enabled variants when the device is configured in standalone mode (no TIA Portal project has yet been downloaded). The relevant article numbers are:

The PROFINET device name field exists on every PROFINET node because PROFINET uses the name (not the MAC) as the device identity. The Basic Panel firmware groups IP and name into the same edit dialog and refuses to commit either if the name is invalid, so a missing or malformed name blocks the IP save as a side effect.

3. Root Cause: The PROFINET Device Name Field is the Real Culprit

On the KP400 Basic PN, the IP, subnet, gateway, and the PROFINET device name are edited in a single dialog. When the user presses Enter on the IP field, the runtime validates the entire dialog. If the device name is empty, contains uppercase characters, contains spaces or underscores, begins with a digit, or contains punctuation, the runtime rejects the entire commit and surfaces the "DNA Compatible" message. The message focuses on "Lower letters" because the most common violation in the field is uppercase letters in a hostname.

The error path is therefore:

1. User opens the IP configuration dialog on the panel.
2. User enters IP, subnet, gateway and presses Enter.
3. Firmware runs ValidateProfinetName(name) on the device name field.
4. If the rule fails, firmware aborts the IP commit and shows the DNA/DNS message.
5. IP field appears unchanged after dismissal because the commit never executed.

There is no path in the runtime to skip the name and save only the IP. The fix is to provide a valid PROFINET device name on the same screen.

4. PROFINET / DNS Naming Rules Explained

PROFINET device names follow RFC 1123 hostname syntax, restricted further to lowercase by the Basic Panel runtime validator. The full rule set enforced by Siemens Basic Panel firmware is:

The validator is strict: even one uppercase letter, one trailing hyphen, or one underscore anywhere in the string will trigger the DNA-compatible error. Examples:

5. Step-by-Step Resolution via the HMI Control Panel

Use this procedure when commissioning a panel that has no project and no IP, or when the user has hit the DNA error and needs to recover without a PC.

1. Power the KP400 and wait for the loader to appear.
2. Open the Control Panel from the loader (tap the Settings icon or use the diagonal arrow button).
3. Tap Network and Dial-up Connections (or Network on newer builds), then double-tap the PROFINET LAN adapter.
4. Set Obtain IP address automatically to Off.
5. Enter the desired IP address (e.g. 192.168.0.2).
6. Enter the Subnet mask (default 255.255.255.0).
7. Enter the Default Gateway if required (e.g. 192.168.0.1). Leave 0.0.0.0 if there is no router.
8. Switch to the Device Name tab (or scroll to the name field on the same screen, depending on firmware).
9. Enter a PROFINET device name that obeys Section 4, e.g. kp400-line1.
10. Tap OK. The runtime will validate the name and, if valid, commit both the IP and the name.
11. Confirm the device reboots the network stack. The loader returns within a few seconds.
12. Verify by re-entering the dialog: the IP and name fields must show the committed values.

If the same error reappears, jump to Section 4 and re-validate the name against the table. The most common repeat failure is a trailing space typed in the field, which the on-screen keyboard does not always make visible.

6. Configuring IP and Device Name from TIA Portal

For projects developed in TIA Portal (V14 SP1 or later is recommended for the KP400 family), the IP and the PROFINET device name are assigned as part of the device configuration, then transferred with the project. This bypasses the on-device validator and is the recommended workflow for production machines.

1. In TIA Portal, open the project and navigate to Devices & Networks.
2. Select the KP400 in the device view and open Properties > General > PROFINET interface [X1] > Ethernet addresses.
3. Set the IP protocol to Set IP address in the project.
4. Enter the IP address, Subnet mask, and (optionally) the Router address.
5. Open PROFINET device name under the same node.
6. Enter the PROFINET device name in lowercase. TIA Portal will warn if the name is not conformant; treat the warning as a hard error before compile.
7. Compile and download the project to the panel using one of the transfer paths in Section 8.

During the download, TIA Portal pushes both the IP and the device name in a single PROFINET naming + IP assignment sequence; the panel applies them as a pair and the runtime never displays the DNA error because the configuration came from a trusted source.

7. Configuring IP and Device Name from WinCC Flexible / ProSave

For legacy projects still maintained in WinCC Flexible 2008 SP3 / SP5, the IP and name can be assigned through ProSave or the WinCC Flexible transfer dialog. The same naming rules apply; the runtime will still validate the name on commit.

1. Connect the engineering PC directly to the panel's PROFINET port or via the plant network.
2. Open ProSave (Start > Siemens Automation > ProSave).
3. Select the device type KP400 Basic color PN.
4. Set the connection type to Ethernet and enter the current IP (factory default is 0.0.0.0 or 192.168.0.1 on some firmware builds; if unknown, hold the panel in transfer mode and use the IP assigned by DHCP from a connected engineering switch, or temporarily set the PC adapter to 192.168.0.1 with a direct cable and try common addresses).
5. In the IP Address tab, set the new IP, subnet, and gateway. Click Set.
6. In the Device Name tab (or the combined dialog on some builds), enter a conformant PROFINET name. Click Set.
7. Reboot the panel for the new values to take effect.

If the IP is unknown, perform a factory reset (Section 11) and start over with a direct cable. Do not assume the panel has a DHCP server enabled; on factory-fresh firmware the panel expects a static IP from the engineering station or from the on-device dialog.

8. Project Transfer and Commissioning

Once the IP and the name are committed, choose one of the following transfer paths. All paths require that the engineering PC can reach the panel on the IP just set; confirm with ping before downloading.

For the PROFINET node commissioning path, open Online > Accessible nodes in TIA Portal, locate the panel by MAC, right-click and select Assign PROFINET device name. Enter the conformant name, click Assign name, then use the same dialog to assign the IP. The name assignment is what allows the IO controller (e.g. S7-1200) to find the panel during PLC HMI connection setup.

9. Verification Procedures

After committing the IP and the name, run the following checks before considering the panel commissioned.

1. On-device check: Re-open the Control Panel > Network dialog. The IP, subnet, gateway, and device name must all show the committed values. If the name field is empty, the commit was not persisted.
2. ICMP reachability: From the engineering PC, run ping 192.168.0.2. A reply within < 5 ms on a direct cable is expected.
3. ARP entry: Run arp -a and confirm the panel's MAC address resolves to the new IP.
4. PROFINET discovery: In TIA Portal > Online > Accessible nodes, the panel must appear with the assigned PROFINET name and the IP just set.
5. PLC connection (if used): From the S7 controller, run the diagnostic buffer and confirm no "PROFINET IO - Station failure" or "DCP - identify duplicate station name" entries.
6. Project download: Transfer a small test project and confirm the start screen appears. If the runtime does not load, the project may have a different IP compiled in than the panel's actual IP; reconcile the two.
7. Name persistence across reboot: Power-cycle the panel and re-check. The PROFINET name and the IP must survive a reboot; if either reverts, the persistent storage write was not acknowledged.

If the IP responds to ping but the panel does not appear in Accessible nodes, the issue is almost always the PROFINET name, not the IP. Re-assign the name using Section 6 step 5.

10. Related Faults and Error Strings

The DNA-compatible message is one of several name-related errors the runtime can surface. Use the matrix below to triage similar symptoms without a second guess.

11. Reset, Restore, and Recovery

When the IP has been set to a value outside the reachable subnet and the panel is no longer reachable, a controlled reset is required.

11.1 Soft reset of network settings only

1. Open Control Panel > System > OP > Reboot.
2. During the reboot, hold the Service key combination (varies by FW; on KP400 it is the leftmost function key + power-on).
3. Select Reset to factory for the network parameters only, or use the loader's Settings > Network & Internet > Reset dialog.
4. Re-enter the IP and name from scratch using Section 5.

11.2 Full factory reset

1. Power off the panel.
2. Hold the Service button (or the equivalent key sequence for KP400) and power on.
3. Confirm Boot in service mode.
4. Use ProSave to perform Restore factory settings.
5. Re-assign IP and name before any project download.

11.3 Recovery from backup

1. Open ProSave.
2. Connect using the panel's current IP (if still reachable).
3. Select Restore and point to the last .psb / .tgz backup.
4. Confirm the IP and PROFINET name in the backup match the engineering plan; if not, re-assign before deploying to the field.

12. Network Planning Reference

Before commissioning, lock down a sub-netting plan that covers both the HMI and the controller, plus reserves for engineering and remote access. The example below is sized for a single-line machine cell with one S7-1200, one KP400, and one engineering PC.

Single-line apparent power and line-current sizing for the panel itself is not the focus of this article; the KP400 is fed from the 24 VDC supply rail. For cabinet-level 24 VDC sizing, use the panel's rated consumption of approximately 7 W plus headroom for the backlight at full brightness. The 24 VDC rail must hold within 19.2 V to 28.8 V at the panel terminals; verify with the cabinet schematic rather than estimating from the supply's nominal output.

13. References in This Article

• SIMATIC HMI HMI devices Basic Panels - Operating Instructions (Siemens Support)
• SIMATIC HMI KTP400 Basic - Device manual
• KP400 Basic - Product support page
• PROFINET commissioning and naming conventions
• PROFINET user organization - device naming
• IEEE 802.1D - MAC bridges (referenced for DNS-conformant labels)

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