Meter validation via the Maxem WebUI for EMS
The WebUI tool allows you, as the installer, to validate the measured values that Maxem receives from a meter on your site.
The goal is simple: we want to make sure the connected energy meters are correctly configured and communicate properly with the Maxem for Energy Management Systems (EMS). Using your own laptop, you'll connect directly to the Maxem. Then you'll use a local web environment (the WebUI) to add meters, configure ports, and test connections. Follow the steps below to make sure the system works properly before you leave the site!
Step 1: What do you need before you start?
Before heading to the site, first gather the right equipment and information. Goal: Make sure you have the necessary equipment to operate the system later.
- A Maxem (Controller)
- A laptop with a network connection (Ethernet port).
- The laptop must be able to automatically accept a network address (DHCP) and support the 'mDNS protocol' (mDNS traffic is sometimes blocked by the firewall).
- A standard network cable (Ethernet cable).
- The PIN code (registration key) of the Maxem. You'll find this on the sticker on the back of the controller.

- An ampere clamp meter to validate the measured values.
Step 2: Connecting the equipment
Now that you're at the Maxem, we'll physically connect your laptop to the device. Goal: Establish a direct communication line between your laptop and the Maxem.
- Make sure you're physically at the Maxem to plug in the Ethernet cable.
- Look at the LAN port on the Maxem. This is where you can plug in the cable. If a switch is connected to this port, you can also connect the laptop to an open port on the switch.
- Now connect your laptop with the network cable directly to this LAN port on the Maxem.
- Note: make sure to properly reconnect the original cable after finishing your work!
Step 3: Connecting to the system
The cable is plugged in, now let's look up the system digitally via your internet browser. Goal: Start up the digital environment (WebUI) of the Maxem on your screen.
- Open the internet browser on your laptop and go to the address: maxem.local.
- Page not loading? Then enter this direct address as an alternative: 192.168.25.1:9999.
- Still not working? Sometimes different networks get confused with each other. Turn off your laptop's Wi-Fi and disconnect any other network cables, so your laptop focuses solely on the Maxem Controller.
Step 4: Logging into the WebUI
You now see the start screen and need to prove you're authorized to change settings. Goal: Log in securely and gain access to the system.
- Once the WebUI login screen opens, enter the secret PIN code found on the back of the Maxem.
- Accidentally typed the wrong code? You'll get a notification and can simply try again.
Figure 1 shows the login screen. This is where you log in with the Maxem's PIN code.
Figure 1: The login screen
Step 5: Setting up and removing meters
This is the core of the task: actually managing and checking the meters. Goal: Ensure all connected meters are correctly set up in the system and successfully communicating with the Maxem.
- Adding a meter: When adding a new meter, choose a name but don't use any special characters.
- Removing a meter: Is there a meter in the list that no longer belongs there? Click the trash can icon (🗑) in the table, located directly next to the 'test' button for that specific meter.
- Configuring RS485 ports: You can only change the settings of ports that are not yet in use. When configuring, always choose the highest 'baud rate' (speed) supported by the meters, so the system runs smoothly.
Figure 2 shows the overview. Here you can configure RS485 ports, such as baud rate, parity, and stop bits. You can also add meters (Figure 3), remove them, and test them in this overview.

Figure 2: The overview
Figure 3: Adding meters
Step 6: Troubleshooting meter issues
Sometimes a test fails and an error message appears. Here's what to do first. Goal: Identify the cause of the faulty connection and resolve it quickly.
- If a meter cannot be read properly (after the 30-second wait time), an error message will appear in the table.
- In that case, always first check whether the physical cable to the meter is properly connected.
- Then check whether you've entered the IP address, the 'Unit ID', and other settings without typos.
Step 7: Testing meters
Once a meter can be read, you can validate the measured values. Validation is an essential part of the Maxem onboarding process. Load Balancing based on incorrect measurement values can lead to overloading of physical components on site or exceeding the contracted power capacity.
- Testing meters: Click the 'test' button next to the meter to check the connection. Does the button seem unresponsive? Wait patiently. A test can take up to 30 seconds.
- Check the amperage per phase with a clamp meter. Do the values not match?
- Check whether the current transformers (CT clamps) are mounted correctly.
- Check the manual for the meter's configuration at https://support.maxem.io/integrated-hardware
- Note when making changes: Have you changed the settings of an RS485 port? Then retest all meters on that port, since your change affects all devices connected to that line.
If, after the last change, all locally measured values match the values shown in the tool, you can move on to the next step.
Step 8: Saving and closing
You've finished the work and want to leave everything in order. Goal: Save your work without data loss and end the session.
- You don't need to look for a "Save" button. The system automatically saves all your changes.
- You can safely close the screen, as long as you don't see a 'loading icon' (spinning wheel) on screen at that moment.
- Inform Maxem.