Bluetooth Communications


Modbus Monitor Advanced App is able to communicate to the remote Modbus device using the Bluetooth Channel. The Modbus Monitor Advanced supports two serial communication protocols to use with the Bluetooth channels.  Once connected via Bluetooth Paring, the read and write registers and coils are supported just like standard serial port Modbus communication.  The Bluetooth Serial Port supports Modbus RTU and Modbus ASCII read and write operations. Following YouTube Video shows many steps listed on this page.



The Bluetooth Serial Port Communication is complected and must be setup correctly for error free communication   The most basic steps will be outligned here but your device may require extra steps and configuration that is not listed here. 


First of all, not all mobile devices may have the Bluetooth Hardware; even if it does, it may not work for Serial Port method of communication via Bluetooth Radio. Check Hardware page to check compatibility before wasting time trying to connect the Bluetooth remote device when your mobile device is incapable. Once the proper Bluetooth hardware is present on your mobile device and the SPP Profile is supported by the Bluetooth stack, next step to check is the Pairing of your device.  The pairing step involves starting the process by searching both devices and entering the correct pairing code.  Check your mobile device's and your Bluetooth Serial Port's documentation for the steps. The device scanning and  pairing can also be done inside the Modbus Monitor Advanced, but it is best to use your Operating System's configuration windows.  The Operating System's Bluetooth Configuration windows shows more error and description.  Once paired, the list of paired devices are shown in the Modbus Monitor Advanced app. 

Before you click "Connect" or touch Bluetooth Icon to start the communication, it is best to verify the settings and the Modbus Monitor Point configuration.  Depending on your Bluetooth device and mobile device's bluetooth stack, the communication settings for "Secure" or "Insecure" connections needs to be setup correctly before successful communication link is established.  Most of the newer mobile devices only supports the "Secure Connections" and thus the "Allow Insecure Connections" options in the Setting screens must be turned OFF.  Otherwise the  "Error #15" will be shown when the Bluetooth device can't establish the serial connections to remote device.  Because there are so many variations of the mobile devices and Bluetooth Serial Ports and we can't cover all of them here, we selected few of the common devices and tested them again various remote devices.  The table below shows the various devices and settings that are tested to give successful connections.  Use that table to save time and set proper configuration for both the mobile device and remote device. 


Once all of the setting are devices are paired properly, you are ready set the Modbus Monitor Point inside the App.  Refer to Parameters page for explanation of "Modbus Monitor Point Setup Dialog".  We will only cover the Bluetooth related setting here.  Click (+) to add the new Modbus Monitor Point or "Change" existing point from the list.  To get the Modbus data from the Bluetooth device, simply select the "Bluetooth" in the "Channel" selection box.  Other important setting is the Protocol selection.  Choose one of the "Modbus RTU" or "Modbus ASCII" protocol for the Bluetooth channel.  If anything other than those protocols are selected, it will be ignored during data collection mode. 

Now the Modbus Monitor Advanced is ready to start the communications with the remote Bluetooth (Serial) device.  Click on the Bluetooth Icon to begin the communication.  If the Bluetooth is not turned on, it will prompt you to turn on the device.  If the permission is given or it has been already paired, the communication begins and data received is shown in the list.