--- title: "Modbus and KNX: configure, test and supervise with Can’nX" description: Declare Modbus gateways and registers, test readings and use the measurements alongside KNX in Boss’nX, Chart’nX, Emergy’nX and Link’nX. canonical: https://wiki.can-nx.com/en/protocoles/modbus/ language: en --- # Modbus and KNX: configure, test and supervise with Can’nX Several Can’nX applications work with Modbus devices alongside the KNX installation: meters, EV chargers, inverter. In Boss’nX and Chart’nX, the process is the same: declare the Modbus gateway with its IP address and port, describe each measurement by its unit ID, register, function code and data type, test the reading, then use the measurement in a component or a dashboard. ## By application **Boss’nX** supervises Modbus datapoints in its components, for reading and for command, alongside KNX and BACnet datapoints. Modbus TCP gateways are declared in **Menu → Modbus gateways**, with the **Manage Modbus** permission. The configurations in the **Modbus registers** tab of **Data logging**, intended for a reading every sixty seconds for the history, can then become read datapoints. - [Add a Modbus gateway](https://wiki.can-nx.com/en/guides/boss-modbus-gateway-create/) - [Configure a Modbus datapoint](https://wiki.can-nx.com/en/guides/boss-point-modbus/) and [test its reading](https://wiki.can-nx.com/en/guides/boss-point-modbus-help/) - [Create a monitoring configuration](https://wiki.can-nx.com/en/guides/boss-modbus-config/) and [import it into a component](https://wiki.can-nx.com/en/guides/boss-import-modbus/) **Chart’nX** feeds the meters of energy and water dashboards from the project’s Modbus catalog. Each Modbus gateway there is linked to the Kloud’nX or Emergy’nX gateway that saves the data. - [Find a configuration in the Modbus catalog](https://wiki.can-nx.com/en/guides/chart-modbus-catalog/) - [Create a Modbus gateway](https://wiki.can-nx.com/en/guides/chart-modbus-gateway/) and [declare a configuration](https://wiki.can-nx.com/en/guides/chart-modbus-config/) - [Test a reading](https://wiki.can-nx.com/en/guides/chart-modbus-test/) and [import submeters](https://wiki.can-nx.com/en/guides/chart-modbus-import/) **Emergy’nX** asks for the Modbus settings of the Terra AC charger and of the Huawei inverter (Modbus TCP), and can read the grid, production and battery measurements from a Modbus **Catalog value**: [configure an EV charger](https://wiki.can-nx.com/en/guides/emergy-evcp-config/), [configure solar production and storage](https://wiki.can-nx.com/en/guides/emergy-building-production-storage/). **Link’nX** declares Evlink Pro AC and Terra AC chargers with their Modbus identifier, then associates their commands with KNX group addresses: [declare the charger](https://wiki.can-nx.com/en/guides/link-charger-devices/), [associate its KNX commands](https://wiki.can-nx.com/en/guides/link-charger-knx/). ## Where to start 1. Gather the manufacturer’s register table: IP address and port, unit ID, register address, function code, data type, scale factor, byte and word order. 2. Declare the Modbus gateway [in Boss’nX](https://wiki.can-nx.com/en/guides/boss-modbus-gateway-create/) or [in Chart’nX](https://wiki.can-nx.com/en/guides/chart-modbus-gateway/), with the right Can’nX gateway. 3. Describe each measurement: [component datapoint](https://wiki.can-nx.com/en/guides/boss-point-modbus/), [monitoring configuration](https://wiki.can-nx.com/en/guides/boss-modbus-config/) or [catalog configuration](https://wiki.can-nx.com/en/guides/chart-modbus-config/). 4. Test the reading and compare the value with the expected measurement. 5. Save, then reopen the item to review the stored settings. ## Good to know - The Boss’nX, Chart’nX and Emergy’nX forms suggest port **502**: keep it only if it matches the device. The **Unit ID** of a Boss’nX datapoint ranges from 1 to 247. - No register address offset is universal: have the correspondence between the manual and the address to enter confirmed. - **INT16** and **UINT16** take one word; **INT32**, **UINT32** and **FLOAT32**, two words. Set byte and word swaps according to the device table, not by trial and error. - A Boss’nX datapoint reads with function codes 1 to 4 and writes with 5, 6 or 16. Its poll interval is at least 5 seconds and its no-signal delay at least three times the poll interval. - In Boss’nX, a reading test does not save the datapoint or the configuration and does not test writing. Import from monitoring copies the settings only once. - In Chart’nX, catalog changes are saved immediately, independently of the dashboard. See also [Energy and metering](https://wiki.can-nx.com/en/usages/energie/), [Water metering](https://wiki.can-nx.com/en/usages/eau/) and [EV charging](https://wiki.can-nx.com/en/usages/recharge/). ## All Modbus guides ### Configuration and use - [Chart’nX battery meter: energy and state of charge over KNX or Modbus](https://wiki.can-nx.com/en/guides/chart-battery/) - [Configure the L1, L2 and L3 phases of a three-phase Chart’nX meter](https://wiki.can-nx.com/en/guides/chart-meter-phases/) - [Configure the KNX or Modbus main meters of a Chart’nX dashboard](https://wiki.can-nx.com/en/guides/chart-meters/) - [Can’nX glossary: KNX group address, DPT, Modbus, kW and kWh](https://wiki.can-nx.com/en/guides/customer-glossary/) - [Emergy’nX solar production and battery: KNX, Modbus or Huawei](https://wiki.can-nx.com/en/guides/emergy-building-production-storage/) - [EV charger (IRVE) in Emergy’nX: model, connection and optimization](https://wiki.can-nx.com/en/guides/emergy-evcp-config/) ### Devices and integrations - [Add an Evlink Pro AC, Lektri.co or Terra AC EV charger in Link’nX](https://wiki.can-nx.com/en/guides/link-charger-devices/) - [Add Daikin, Gude or Atmoce devices in Link’nX: IP, port and Slave ID](https://wiki.can-nx.com/en/guides/link-dga-devices/) ### Protocols, imports and monitoring - [Import Modbus monitoring configurations into a Boss’nX component](https://wiki.can-nx.com/en/guides/boss-import-modbus/) - [Configure a Modbus register reading for history in Boss’nX](https://wiki.can-nx.com/en/guides/boss-modbus-config/) - [Add or edit a shared Modbus TCP gateway in Boss’nX](https://wiki.can-nx.com/en/guides/boss-modbus-gateway-create/) - [Duplicate, disable or delete a Modbus gateway in Boss’nX](https://wiki.can-nx.com/en/guides/boss-modbus-gateway-manage/) - [Configure a Boss’nX Modbus datapoint: read and write a register](https://wiki.can-nx.com/en/guides/boss-point-modbus/) - [Archive, restore or delete a Modbus configuration in Chart’nX](https://wiki.can-nx.com/en/guides/chart-modbus-archive/) - [Chart’nX Modbus catalog: find a meter configuration](https://wiki.can-nx.com/en/guides/chart-modbus-catalog/) - [Declare, edit or duplicate a Modbus configuration in Chart’nX](https://wiki.can-nx.com/en/guides/chart-modbus-config/) - [Create, edit or disable a Modbus gateway in Chart’nX](https://wiki.can-nx.com/en/guides/chart-modbus-gateway/) - [Import Modbus configurations as Chart’nX submeters](https://wiki.can-nx.com/en/guides/chart-modbus-import/) - [Test a Modbus reading in Chart’nX: result and unavailable test](https://wiki.can-nx.com/en/guides/chart-modbus-test/) ### Questions and troubleshooting - [Test a Modbus register read and troubleshoot monitoring in Boss’nX](https://wiki.can-nx.com/en/guides/boss-modbus-config-help/) - [Boss’nX Modbus datapoint: test the reading and fix errors](https://wiki.can-nx.com/en/guides/boss-point-modbus-help/) - [Chart’nX energy meter: troubleshooting and frequently asked questions](https://wiki.can-nx.com/en/guides/chart-meter-help/) - [Modbus in Chart’nX: missing measurements and frequently asked questions](https://wiki.can-nx.com/en/guides/chart-modbus-faq/)