Knowledge · commissioning

Commissioning the EMU M-Center with the H2O and DELTA III

How to integrate Helvatron water meters and heat meters into an EMU M-Center: from first access via the service port to the readings in the control system or in Joulio-Web. The M-Center is a product of our sister company EMU Electronic AG.

Preparation

What do I need for commissioning?

  • EMU M-Center on a DIN rail, supplied with 230 V AC
  • Laptop with a network port and an up-to-date browser, network cable (RJ45)
  • H2O and DELTA III with M-Bus (suffix ABM) or with RS-485 Modbus RTU (suffix ABMO); for the DELTA III, also both together (ABMM)
  • Licences in the M-Center for the number of meters and the protocols required
  • List of meters with serial number, location and medium; for Modbus, also the slave addresses and register list

A practical tip

The serial number is also printed as a QR code on every H2O and DELTA III. Scan the codes during installation and note the location next to each one. With this list, you can assign the meters in the M-Center in a few minutes.

Step 1

How do I connect to the M-Center?

For first access, use the service port (the lower network port). It has the fixed address 169.254.254.1 and automatically assigns an IP address to the laptop.

Modbus C B A C B AM-BUS Master EMU M-Center M-BUS | Modbus | MQTTOPC UA | BACnet IP 10:2C:EF:02:6C:B9 SupplyFLEX I/O 1FLEX I/O 2USB-C Service port = lower port LAN = upper port Laptop IP address assignedautomatically via DHCP http://169.254.254.1 Enter the address in the browser Log in admin 123 Log in
  1. Plug the cable into the service portThe M-Center has two RJ45 ports: LAN at the top and the service port at the bottom, for a direct connection to a laptop.
  2. Connect the laptopConnected to the service port, the laptop is automatically assigned an IP address via DHCP. You do not need to change any network settings.
  3. Open the web interfaceEnter the fixed address http://169.254.254.1 in the browser.
  4. Log inFactory setting: username admin, password 123. Change the password after logging in for the first time.

Change the factory password immediately after logging in for the first time.

Step 2

How do I connect the H2O and DELTA III?

Via M-Bus

  • Two wires to the M-BUS Master terminal; polarity does not matter
  • Star, line and tree topologies are possible, but not a ring. Keep cables as short as possible
  • Water and heat meters can share the same line
  • On the M-Bus, the H2O and DELTA III run on battery power. Bus power is available as an option, for the DELTA III with backup battery

Via RS-485 (Modbus RTU)

  • The M-Center has two RS-485 lines (terminals A, B, C)
  • One line per bus, from meter to meter, with 120 Ω at both ends
  • Use each slave address only once per line; same baud rate and parity for all devices
  • A DELTA III with M-Bus and RS-485 (ABMM) can serve both paths in parallel

Step 3

How does the M-Center find the Helvatron meters?

Set the time and time zone first. Otherwise the readings will have the wrong timestamps, and billing-date values will end up on the wrong day.

Then start the M-Bus scan. The M-Center finds the meters by their secondary address; Helvatron devices identify themselves with the manufacturer code HVT. After the scan, check that the number of devices found matches your list.

Check the medium

The M-Center assigns each meter to a category. Check that the H2O appears under water and the DELTA III under heating or cooling. If a device is in the wrong category, the medium can be changed in the M-Center afterwards.

Reading interval and battery

The default is 15 minutes. For battery-powered meters, it is worth reviewing the interval: the DELTA III achieves 18 + 1 years with reading every 15 minutes and 19 + 1 years with reading every 12 hours. For billing, hourly or daily values are often sufficient, and the meter stores these in its own memory anyway.

Good to know

  • The M-Center only reads as many M-Bus devices as it is licensed for. Additional meters on the bus are ignored but still add to the bus load.
  • Each meter draws a standard load of about 1.5 mA. For large installations, match the M-Center supply accordingly.
  • If a reading cycle takes longer than the interval, increase the interval or set it individually for each device.

Step 4

How do I integrate the H2O and DELTA III via Modbus RTU?

On RS-485, set up each meter as a Modbus device: line, slave address, baud rate and parity. Then map the registers the M-Center is to read, with function code, data type, unit and word order.

We will send you the register list for the H2O and DELTA III on request. Set up the mapping carefully for the first meter and check the values before copying it to other meters of the same type.

Request the register list

Common pitfalls

  • No response: address, baud rate or A/B swapped
  • Sporadic errors: termination resistor missing or doubled
  • Implausible values: wrong data type or word order

Step 5

Which values should I see, and are they plausible?

H2O water meter

  • Total volume, forward and reverse volume
  • Current flow rate
  • Error codes, such as air in pipe, leak or battery

Plausible? Compare the reading in the M-Center with the display on the meter. If the reverse volume keeps increasing, the meter may have been installed against the direction of flow.

DELTA III heat meter

  • Heating energy and cooling energy in separate registers
  • Volume, power, flow rate
  • Flow temperature, return temperature and temperature difference
  • Error code and alarm time

Plausible? In a heating system, the flow must be warmer than the return. If a heating plant records cooling energy, the sensors have usually been swapped or the flow sensor is in the wrong pipe.

Step 6

How do the values reach the control system and Joulio-Web?

The M-Center forwards the H2O and DELTA III values via MQTT, BACnet IP, Modbus TCP or CSV. BACnet IP or Modbus TCP is typical for building automation, and MQTT for cloud services and dashboards.

Setting up Joulio-Web

  1. In the M-Center, go to Settings → Joulio-Web and select ‘Active’.
  2. Upload the certificate file (.pem) you receive from Joulio-Web.
  3. Enter your client ID and save. The upload starts immediately.

For Helvatron meters, Joulio-Web offers the ‘EMU and Helvatron meters’ licence (item 250.000.01).

H2O and DELTA IIIM-Bus or Modbus RTU
EMU M-Centerreads, stores, converts
Control system · Joulio-WebBACnet IP, Modbus TCP, MQTT, CSV

Handover

What should the handover include?

Change the password

Replace the factory password and create separate users with suitable rights for operators and service providers.

Back up the configuration

Export the entire configuration as a file, after commissioning and after every major change.

Document

Note the meter number, location, medium, address and meter reading at commissioning.

Firmware updates, user management and all M-Center functions are described in detail by EMU on emuag.com.

Would you like support with commissioning?

We can help you integrate the H2O and DELTA III, set up the register mapping and check the values for plausibility.

Technical advice

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