The connected products are not visible in the 3SModbus configuration software
How a Modbus network works
A Modbus RTU network is always composed of 1 master device and one or more slave devices. The master requests information from one of the slave devices and the slave device answers that question. The master can also give a command to one of the slave devices. In that case, the slave device will execute the command. It is essential that every device that is part of the Modbus network has a unique address. This is the only way the master can address the right slaves individually.
A computer with 3SModbus configuration software can be seen as the master of a Modbus network. When multiple devices with identical slave address are connected this computer, they cannot be visualized. Only when they all have a unique Modbus address, the connected devices will become visible in the 3SModbus configuration software.
A unique address for each device
All new Sentera devices have Modbus address 1 as default factory setting. When multiple new devices are connected at the same time, a PC with 3SModbus configuration software cannot immediately address or detect these devices. First, the new devices must all be assigned a unique Modbus address (preferably different from 1).
There are two ways to do this:
Change the Modbus address of one individual connected device manually
In this case each device must be individually connected to the computer with 3SModbus software. The PC with 3SModbus software acts as the master of the Modbus network. If one device is connected with Modbus address 1, this will be visualized. (If multiple devices with the same address are connected, they cannot be visualized.) The parameters of the connected device can be read by clicking on the icon of the device. The Modbus address of the connected device can be changed via the Holding registers.
Change the Modbus addresses of all connected devices automatically
If multiple devices are simultaneously connected to the PC with 3SModbus software, the key combination Ctrl + Alt + A can be pressed. This ensures that the 3SModbus will automatically provide all connected devices (including those that are not visible) with a free Modbus slave address. After pressing this key combination, all connected devices will be visible if they have been connected correctly.
3SModbus software is a part of the 3SM Center software suite. It is a tool to configure Sentera products via Modbus RTU communication or to update the firmware. Sentera developed this free software suite 3SMCenter, which you can download from our website. Its intuitive interface facilitates the process of configuration, monitoring and updating of Sentera products via Modbus RTU communication.
To connect Sentera devices to the computer with 3SModbus software, we advise to use the CNVT-USB-RS485-SET connection set.