Create a Chart’nX water meter group: primary and secondary meters

In a Chart’nX water dashboard, a group brings together a primary meter and its secondary meters, KNX or Modbus. The primary is either a real measurement or the virtual sum of its secondaries. Each group forms one layer of the distribution pie chart.

Intended for administrators and installers.

Before you start

• The water dashboard is open with Configure and its general information is filled in.
• The unit and the KNX address or Modbus configuration of each measurement are known.

Create the group and its primary

1. In Sub-meters, click + New group. A group card appears with 1 primary and the number of secondaries.
2. In its Primary card, fill in Meter name. Fictitious example: “Water floor 1”.
3. Choose Real if you have a dedicated measurement for the primary, or Virtual (∑ secondaries) if the primary must be the sum of the secondaries of this group.
4. For a Real primary, choose Protocol, Index or Not indexed, then the KNX Group address or the Modbus Configuration, the Meter unit of measurement and the Custom Factor. Use the known parameters of the measurement, as for the total water meter. For a custom calculation, follow Compose a water calculation.
5. For a Virtual (∑ secondaries) primary, the protocol and address fields are replaced by the sum indication. Keep a name and choose its unit. Then add at least one secondary, otherwise the group cannot be validated.

Switching from Real to Virtual (∑ secondaries) changes the meaning of the primary. To return to Real, check all its parameters again, especially the address or the Modbus configuration: an old setting may no longer match the installation.

Add the secondary meters

1. In the group, click the + Add secondary meter card.
2. Give the added meter a name, then fill in its protocol, its measurement, its unit and its factor. Repeat for the other measurements.
3. For several existing Modbus configurations, use Import modbus in the header of this same group, according to the import procedure.
4. Under a virtual primary, each secondary has a Count in the group total box, checked initially. Uncheck it if this meter is already measured by another secondary (nested meter). The Include in the total pie chart box is then unchecked and locked.

Set the units and the display

1. For each meter of the group, primary included, choose the unit actually received: Liter (L), Kiloliter (kL) or Cubic meter (m³). A group can mix these units: Chart’nX converts the values to liters before combining them.
2. Keep the Custom Factor for the metering ratio, for example 10 units per pulse, not for converting a unit. Ask the installer if in doubt.
3. Add the useful presence overlays with + Add overlay, as for the total meter.
4. On each secondary, check Display: Show in chart and Include in the total pie chart. Both boxes are initially checked; they control the display without removing the card from the form.

Check the result

Save the dashboard, then open it over a period in which you expect data: check the composition of the group and compare the primary’s value with those of its secondaries. You can then choose the group’s color and the order of the cards.

Troubleshooting

• “a virtual primary needs at least one secondary meter”: add a measured secondary, or return to a real primary if that is indeed the intended installation.
• The sum of the virtual primary looks wrong: check the Count in the group total box of each secondary.
• For an inconsistent volume or a refused save, follow the water dashboard troubleshooting.

If the expected composition remains uncertain or if validation is blocked after these checks, contact support@can-nx.com with the name of the primary, the message and the checks made.