Key Takeaway
To find a Siemens PLC IP address (S7-1200, S7-1500, etc.):
Connect your PC to the PLC’s Ethernet port.
Open TIA Portal, select “Online Access,” and scan the accessible devices.
The PLC’s assigned IP address will appear in the accessible devices list.
Alternatively, many CPUs have an onboard display (HMI) showing the IP address under “Settings” > “Ethernet Interface.”
If using an unmanaged network, tools like Primary Setup Tool (PST) or Siemens Accessible Devices Utility can detect PLCs.
In case of unknown settings, the CPU might default to DHCP mode or use a factory-set IP.
Proper IP identification is crucial for remote programming, diagnostics, or SCADA communication setup.
Default IP Settings and Manual Configuration
When you first unbox a Siemens PLC, especially models like the S7-1200 or S7-1500, it might come with a default IP address, or sometimes, no IP at all (factory reset mode). That means it will either be waiting for a dynamic IP from a DHCP server or for you to assign one manually.
The default IP range for many Siemens PLCs is 192.168.0.x. But, it’s not safe to assume! You should always confirm by checking the product manual or using a setup tool (we’ll cover that shortly).
Manual configuration is straightforward once you’re inside TIA Portal. Just connect your laptop via Ethernet to the PLC, open your project, and navigate to the device configuration. Here, you can assign a static IP under the “Ethernet addresses” tab.
Pro tip: Always pick an IP that’s within your subnet and not already used by another device. Maintain a consistent IP naming convention across your plant for smoother troubleshooting later.
Using TIA Portal to Discover IP Address
Now let’s say you’re unsure of the PLC’s IP address and it’s not labelled anywhere. No worries — Siemens thought of this.
Open TIA Portal, go to Online Access on the project tree, and scan your network using the “Accessible devices” function. If your PLC is powered on and properly connected, it should pop up here, showing its current IP, MAC address, and model number.
Once you spot the device, you can directly assign a new IP or even upload its existing configuration to TIA. It’s a clean and visual way to manage devices, especially in large factories.
This method is super helpful when taking over an existing system or when a PLC’s label is worn out or missing. It also eliminates the need to reset anything unless absolutely necessary.
Accessing Device Information from the Network
Sometimes, you’re not working with a fresh install. Maybe someone else set it up. Maybe documentation is missing. But you still need to find that IP address.
In that case, scan your network using tools like Advanced IP Scanner or Angry IP Scanner. These tools list all connected devices and can often identify Siemens PLCs based on their MAC vendor info or hostname.
Once found, you can ping the device, access its web server (if supported), or jump back to TIA Portal for programming or diagnostics.
Important tip: Make sure you’re connected to the same subnet. If the PLC is on a different VLAN or isolated switch, this method won’t work until you bridge the gap.
Tools like Primary Setup Tool (PST)
Before TIA Portal became the standard, Siemens offered (and still supports) a small tool called Primary Setup Tool (PST). It’s lightweight, easy to install, and can detect all Siemens devices on a local subnet — even if their IP isn’t set.
You can use PST to assign a temporary IP, rename the device, or set permanent network settings. It’s especially useful for older CPUs, HMIs, or even basic communication modules that don’t play nicely with TIA Portal.
The only requirement? You need to be on the same Layer 2 network (same switch or broadcast domain). PST uses MAC-level broadcast to find devices, which doesn’t route across subnets.
PST is still beloved by many field engineers who prefer its speed and simplicity when dealing with legacy devices.
Troubleshooting IP Conflicts and Connectivity Issues
Got the IP but still not able to connect? Let’s troubleshoot like a pro.
First, ensure no two devices on the network share the same IP. Duplicate IPs are a silent killer — sometimes everything looks okay but devices keep dropping randomly.
Second, check subnet masks and gateway settings. A misconfigured subnet can make a PLC unreachable even if it’s powered and healthy.
Third, disable your firewall temporarily while testing. Some antivirus or OS firewalls block ping responses or programming port traffic.
If you suspect a bad cable or port, swap it. Try a direct connection between your laptop and the PLC using a known-good Ethernet cable. Eliminate external variables one by one.
Also, when nothing works, and you have physical access, consider doing a factory reset (check the model’s manual). But only do this when you’re sure configuration can be reloaded safely!
Conclusion
Knowing how to locate, assign, and troubleshoot a Siemens PLC IP address is a must-have skill for any automation engineer. From TIA Portal to Primary Setup Tool, and even simple IP scanning tricks, you now have multiple ways to get the job done.
When in doubt, always work methodically. Start simple: check labels, use TIA, scan the network. Keep a log of all IPs you configure. In larger plants, maintain a spreadsheet of all devices with IP, MAC, and purpose.
Remember, your PLC is the brain of your automation system. And its IP address? That’s its voice on the network. Make sure it speaks clearly, and you’ll save yourself from endless headaches down the line.