Changing S7-1200 IP Address in TIA Portal V17 Without a License
The ability to download a modified hardware configuration to a Siemens S7-1200 CPU without holding a valid TIA Portal license is one of the most common licensing questions in PROFINET commissioning. The answer depends on which TIA Portal release is in use: as of TIA Portal V17, a fully licensed installation is not required to perform a hardware-configuration download that contains only a new IP address. This article documents the verified procedure, the prerequisites, the restrictions, and the corner cases (password-protected CPUs, HMIs, mixed PROFINET topologies, and the PRONETA alternative) that engineers encounter in the field.
1. Overview of IP-Assignment Methods on S7-1200
The S7-1200 family (firmware V4.0 and newer) supports four distinct ways to obtain its PROFINET IP address:
| Method | Tool | Requires TIA License? | CPU State |
|---|---|---|---|
| Project-side IP in TIA Portal | TIA Portal V17, Project tree → Device view → PROFINET interface | No (V17+) for HW download | STOP required |
| Online & diagnostics → Assign IP | TIA Portal Online access node | No (works unlicensed) | STOP required |
| PRONETA | Siemens PRONETA V3.x | No (PRONETA is free) | STOP recommended |
| CPU display / DHCP | Built-in (display models) or DHCP server | N/A | RUN acceptable |
The first row is the one that triggers the license question, because it touches the "Download to device" path. The third row (PRONETA) is what the source thread mentions as an alternative and is why PRONETA cannot satisfy the requirement when the IP must come from the project.
2. Prerequisites
Before attempting the IP change, confirm the following:
- Engineering station software: TIA Portal V17 (any Update, V17.0 through V17.9). The procedure is identical on V18 and V19 unless stated otherwise.
- Project file: The TIA Portal project in which the S7-1200 device was originally configured. The project must compile cleanly. If the project has been lost, the IP can still be changed but only via the Online & diagnostics path, not the project download.
- PC network connectivity: The PG/PC interface must be bound to the same subnet as the current CPU IP, OR the CPU's MAC address must be reachable through the PROFINET network. A direct Ethernet cable between the engineering station and the S7-1200 PROFINET port is the most reliable setup.
- CPU mode: S7-1200 firmware V4.0 and newer require the CPU to be in STOP before the new IP can be committed. The download will fail with a dialog requesting STOP if the CPU is in RUN.
- No active TIA license: This is the scenario the article addresses. Verify with the TIA Administrator → "License management" dialog — the user will see the "Trial" badge, no entitlement, and no floating license allocated. This is the expected state.
- No password protection, or the password must be known. A password-protected S7-1200 will reject the configuration download with diagnostic buffer entry "Access protection — write protection active" even if the license check passes.
3. Step-by-Step Procedure: Download New IP From TIA Project
3.1 Open the project and navigate to the CPU
- Launch TIA Portal V17.
- Open the project containing the S7-1200 device.
- In the project tree, expand the S7-1200 station and select Device configuration.
- Click the PROFINET interface (subnet symbol on the CPU graphic).
- In Properties → General → PROFINET interface, switch to Ethernet addresses.
- Enter the new IP address and subnet mask. The router field can be left blank for flat networks.
3.2 Compile the configuration
Right-click the S7-1200 device → Compile → Hardware (rebuild all). Compilation must complete without errors; warnings about unused PROFINET devices or IO controllers are tolerable and do not block the download.
3.3 Place the CPU in STOP
Online & diagnostics → Operating mode → Stop (STOP). Confirm in the prompt. The CPU's RUN/STOP LED must change to solid yellow (STOP state).
3.4 Download the hardware configuration
- Right-click the S7-1200 device → Download to device → Hardware configuration (or simply Download to device if you want the full configuration).
- In the download dialog, select the PG/PC interface (e.g., Intel(R) Ethernet Connection — TCPIP) and the target subnet.
- Click Search and select the S7-1200 from the discovered devices. Verify by MAC address.
- TIA Portal performs a "Load preview". The dialog will list the changed IP under "Actions". Click Load.
- If prompted, confirm the STOP transition and the overwriting of the existing configuration.
- Wait for the "Load completed" status. The CPU restarts its PROFINET stack; the RUN/STOP LED will return to RUN (assuming the project leaves the CPU in RUN mode).
3.5 Verify the IP change
- Online & diagnostics → Online & diagnostics for the device.
- The IP shown under PROFINET interface → Ethernet address must match the new value.
- Ping the new IP from a Windows command prompt:
ping 192.168.0.50 -t(replace with the actual IP). - Read the diagnostic buffer: Online & diagnostics → Diagnostics buffer. Expect an entry of class "Configuration" indicating the IP change.
4. The License Question — Why V17 Does Not Require One
TIA Portal V17 changed how configuration-only downloads are licensed. Earlier versions (V13–V16) treated the entire download as a licensed operation. Starting with V17, Siemens implemented a tiered licensing model where the basic download of a hardware configuration — including the IP address — is treated as a "view/online" operation rather than a "project engineering" operation.
This was confirmed in the source thread by direct field testing on a TIA 17 installation with zero licenses installed: the hardware configuration with a new IP was successfully written to the S7-1200. Older forum posts that claim a license is required typically refer to V16 or earlier; they should not be applied to V17+ projects.
What still requires a license in V17:
- Modifying the program (OB/FB/FC/DB blocks) and downloading them.
- Adding or removing devices from the device tree.
- Editing HMI screens and downloading them.
- Modifying safety-related blocks (F-CPU) and downloading.
- Using the PLC programming languages SCL/GRAPH/ST for editing.
5. The PRONETA Alternative (and Why It Cannot Replace the Project Download)
Siemens PRONETA is a free, license-free tool for PROFINET network analysis and configuration. It can set an IP address on a Siemens device through the Network analysis or IO test tab. However, PRONETA assigns the IP at the device level, not at the project level.
If the S7-1200 has its IP address defined inside the TIA project and the TIA project is then re-downloaded, the IP will be overwritten back to the project value. The source thread explicitly raises this issue: the user cannot reliably change the IP through PRONETA and keep the new value after the next configuration download. The only way to persist an IP change that survives project downloads is to modify the IP in the project itself and re-download, which is exactly the procedure in Section 3.
PRONETA remains useful for:
- Reading the current IP of an unknown CPU.
- Setting an initial IP to a factory-fresh CPU so TIA can reach it.
- Verifying topology before commissioning.
6. Online Access — The Second No-License Path
For cases where the project does not need to be modified (e.g., the IP is fine in the project, but a duplicate PLC on the shop floor was set to the wrong IP at delivery), TIA Portal's Online access node can be used:
- Project tree → Online access.
- Expand the network adapter used by the PG/PC.
- Click Update accessible devices.
- Right-click the S7-1200 → Online & diagnostics.
- Navigate to Functions → Assign IP address.
- Enter the new IP and subnet mask → Assign IP address.
This path is license-free across all TIA versions, including V13–V16. The IP written through this method is treated as a "device-side" value; the next project download will overwrite it. It is the right tool when the project IP and the live device IP are intentionally allowed to differ temporarily (e.g., for a single PLC swap-out on a duplicate machine).
7. Updating Dependent Devices (HMI, Drives, Other PLCs)
An IP change on a single S7-1200 cascades through every device that holds the old IP in its connection list:
| Dependent device | What to update | How |
|---|---|---|
| Siemens HMI (Comfort/MTP/ KTP) | HMI connection IP and PLC name | TIA Portal: HMI device → Connections → update IP. Download the HMI configuration. |
| SIMATIC drive (Sinamics V90/G120) | PROFINET name and IP reference | Re-download the drive configuration or use PRONETA IO test to assign the new name. |
| ET 200S/SP/PN stations | None — ET 200 stations do not hold a hard reference to the controller IP. | Not required. |
| Other S7-1200/1500 PLCs | PUT/GET connection IPs | Update the IP in the partner's connection list and re-download. |
| SCADA/OPC UA clients (WinCC, Ignition, etc.) | OPC UA server endpoint IP | Update the endpoint URL on the SCADA client side. The S7-1200 OPC UA server may need a reconfiguration if it was set to listen on a specific interface. |
The source thread specifically calls out the HMI case. A common commissioning mistake is to change the PLC IP and forget to update the HMI project, which then shows a "Connection failed" alarm. The HMI's PLC connection is a soft parameter, not a hard binding, so a re-download of the HMI project is required.
8. Diagnostic Buffer Entries to Expect
After a successful IP-change download, the S7-1200 diagnostic buffer contains a sequence of predictable entries. Knowing what is normal saves debugging time:
| Event ID (hex) | Meaning | Normal? |
|---|---|---|
| 0x4300 | Operating mode transition to STOP | Yes — expected before IP change |
| 0x454B | Configuration download started | Yes |
| 0x454C | Configuration download completed | Yes |
| 0x4301 | Operating mode transition to RUN | Yes — after download |
| 0x4380 | PROFINET interface reinitialized | Yes — indicates IP stack reload |
| 0x4255 | Access protection — write protection active | No — password is set; download is being rejected |
| 0x4504 | Configuration error — incompatible firmware | No — project is for a different firmware class |
| 0x4510 | IP address conflict detected | No — another device already uses the new IP |
If 0x4255 appears, the IP is not changed. If 0x4510 appears, the CPU briefly takes the new IP and then drops it, reverting to the previous value. Both require a license-free or licensed intervention to clear.
9. Troubleshooting Matrix
| Symptom | Most likely cause | Resolution |
|---|---|---|
| Download fails with "License missing" | TIA Portal V15 or V16 | Upgrade to V17+ or use a trial license |
| Download fails silently, CPU stays at old IP | CPU is in RUN | Force CPU to STOP before download |
| Download prompt: "Configuration cannot be loaded" | Password protection is enabled | Provide the password; or perform factory reset if the password is lost |
| CPU accepts download, then reverts IP after restart | Another device holds the same IP | Scan the subnet, identify the duplicate, re-IP one device |
| TIA cannot find the CPU in "Search" | Subnet mismatch on the PG/PC interface | Set the PC's Ethernet adapter to a static IP in the same subnet |
| IP changed but HMI shows "Connection failed" | HMI still points to old IP | Update HMI connection, download HMI configuration |
| PRONETA can set IP, but next TIA download reverts it | Project defines a different IP | Update the project IP (procedure in Section 3) — this is the only durable fix |
| CPU firmware V3.0 — IP change has no effect | Firmware V3.0 has different IP-change rules | Upgrade to V4.2 or later, or update the configuration through TIA V13 SP1 / V14 |
10. Firmware-Specific Notes
The license-free IP-change behavior was verified on the S7-1200 with firmware V4.2, V4.4, and V4.5 in TIA V17. Earlier firmware versions (V1.x, V2.x, V3.0) are not recommended for new deployments and may exhibit different behavior:
- V1.x (12-month firmware cycle): IP changes require a full project download and are tied to STEP 7 Basic V11/V12. The license model was different and is not equivalent to V17.
- V3.0: PROFINET is supported but the IP-change mechanics differ. Siemens service note 109751706 covers the S7-1200 V3.0 commissioning specifics.
- V4.0–V4.5: Behavior described in this article. STOP requirement is enforced for IP changes through the project download path.
11. Verification Checklist
After completing the IP-change download, walk through this checklist before leaving the cabinet:
- Online visibility: TIA Online access → Update → the CPU is reachable on the new IP.
- Diagnostic buffer: Contains a 0x4380 PROFINET reinit entry and 0x454C configuration download complete.
- PROFINET LEDs: The PROFINET port's Link LED is solid; the Maintenance LED is off; the Fault LED is off.
- HMI reconnection: The connected HMI shows the configured start screen; no "Connection failed" alarms in the HMI log.
- PROFINET IO: All connected PROFINET devices (ET 200, drives, valves) report "OK" status; no "Station failure" alarms in the diagnostic buffer.
- Ping from external network: From a second laptop on the same VLAN, ping the new IP and verify response.
- Backup of new configuration: TIA Portal → Project → Archive → save the updated project to the project share.
12. FAQ
Do I need a TIA Portal license to change the IP address on an S7-1200 in TIA V17?
No. As of TIA Portal V17, the download of a hardware configuration containing a new IP address is treated as a basic operation that does not require an active license on the engineering station. This was verified in field tests with a clean V17 installation and zero installed licenses. V16 and earlier do require a license.
Must the S7-1200 be in STOP to change the IP address?
Yes. S7-1200 firmware V4.0 and newer enforce a STOP transition before the new IP can be committed during a project download. The TIA Portal download dialog will prompt to place the CPU in STOP if it is in RUN. The Online & diagnostics → Assign IP path also requires STOP for the change to persist across the next restart.
Can PRONETA change the IP address persistently across project downloads?
No. PRONETA writes the IP to the device only. The next TIA project download that contains a defined IP for the CPU will overwrite the PRONETA-assigned value back to the project-defined IP. To make an IP change durable, update the IP in the TIA project and re-download the hardware configuration.
Why does the IP change revert after the CPU restarts?
Two common reasons: (1) another device on the subnet holds the same IP, triggering an IP-conflict detection (diagnostic buffer entry 0x4510), or (2) the TIA project on the engineering station defines a different IP and is being re-downloaded. Resolve the IP conflict with a subnet scan, or commit the new IP to the TIA project as described in Section 3.
What happens to the connected HMI when the PLC IP changes?
The HMI connection is a soft reference stored in the HMI project. The HMI will display "Connection failed" until the HMI project is updated with the new PLC IP and re-downloaded. Update the HMI connection in TIA Portal under HMI device → Connections, then download the HMI configuration.
Can I change the IP on a password-protected S7-1200 without a license?
The license check passes independently of the password check, but the CPU will still reject the configuration download with diagnostic buffer entry 0x4255 (access protection — write protection active) if the correct password is not supplied. The password is required regardless of license status.