Adding a New Modbus Device

To add a new Modbus device to your controller configuration, follow these steps:

1. Click the Add device button in the Modbus tab.

2. Configure the parameters in the Modbus device dialog as follows:

   • Connection type:

     • Choose either RTU (RS-485) or TCP/IP as the connection type for your Modbus device.

   • Name:

     • Define a name for the Modbus device.

   • Status object:

     • Monitor the connection status with the Modbus device using the Status object.

     • When communication is disrupted, the status object is set to 0.

   • Write to bus:

     • Enable sending data to the KNX TP bus.

     • If disabled, telegrams to KNX TP are not sent when the Modbus value changes. Telegrams are still sent to KNX IP.

   • Profile:

     • Select the Modbus profile for your device.

     • You can use a preinstalled profile or upload a custom device profile to the controller.

     • Refer to the procedure for creating a new profile definition (Creating a New Modbus Device Profile).

   • Device address:

     • Set the extension address of your Modbus device.

   • Poll interval (seconds):

     • Specify how often values are polled from the Modbus extension device.

     • A value of 5 means new values are read every 5 seconds.

   • Timeout (seconds):

     • If there is an error in the connection, the device will wait for the specified time and then send an error message to the Error log.

   • IP (Modbus TCP):

     • If you are using Modbus TCP, set the IP address of the Modbus device.

     • If the Modbus device is connected via a Modbus gateway, set the gateway IP address here.

   • Port (Modbus TCP):

     • Set the port for Modbus TCP communication.

     • The default value according to the Modbus standard is 502.

   • Persistent connection:

     • When enabled, the connection remains open.

     • When disabled, the controller reads all registers and disconnects.

   IMPORTANT: Some Modbus TCP/IP devices may not handle frequent (re)connections well (e.g., panel servers, inverters, Modbus meters). Consider using the Persistent connection option if your polling interval is less than a minute.