LM048: Remote Configuration via USB Adapter or in-Built Bluetooth of PC

This article describes remote configuration of LM048/LM058 Adapter using a Bluetooth USB Adapter or in-built Bluetooth of PC/Laptop. For Setup procedure please look at the article LM048: Remote Configuration of Serial Adapter via Bluetooth Connection

The remote configuration procedure is described using a Windows 7 Professional Desktop PC with Bluetooth USB Dongle, LM149 Software and Hercules Setup Utility Serial Terminal. The same instructions apply if you are using a device (e.g. notebook or tablet) with built-in Bluetooth.

Setting up Virtual COM port for Serial Adapter

Follow the below steps to configure serial adapter over Bluetooth.

  • Power up the Bluetooth Serial Adapter. The LED status should be RED: ON, BLUE: Blinking, AMBER/GREEN: OFF
  • Insert the Bluetooth USB Adapter and discover the serial adapter (right-click on the system tray Bluetooth icon and then Show Devices) and add to Bluetooth Devices. A virtual Serial Port can then be created as shown in screenshots below





  • Check the services tab of Bluetooth Device find the virtual Bluetooth COM port number


Remote Login Authentication Disabled

Remote Configuration using Serial Terminal

After adding the Bluetooth Serial Adapter to PC Bluetooth Devices, user can also use a serial terminal program instead of LM149 Software. The below steps are shown using Hercules Setup Utility Serial Terminal on a Windows 7 PC.

1/ Open the Bluetooth Virtual COM Port. This will create the Bluetooth connection with the Serial Adapter.


2/ Make sure the End of Line (EOL) character setting is set to Carriage Return (CR) on the serial terminal


3/ Send the handshake sequence 0xAA 0xAA 0xAA 0xAA 0xAA 0xAA 0xAA 0xAA 0x0D as Hex characters or via “Send File” feature depending on the Serial terminal feature. The handshake file can be downloaded from here handshake.txt


4/ Once the handshake sequence is processed the user will get a reply 0xBB 0xAA when authentication is disabled or 0xBB 0xBB when authentication is enabled


5/ When handshake sequence is complete, user can send AT Commands and get a response. The user can use AT Commands to read or change settings. Please refer the LM048 AT Command Manual for the list of all AT Commands. Please note user will not see echo of AT Commands sent to LM048 but only responses as shown in the screenshot below for command AT, AT+VER, AT+ENQ


6/ To exit remote configuration, send AT+AUTO command. OK response will be received and the remote serial adapter will switch back to data mode. To disconnect the connection, please close the COM port.


Remote Login Authentication Enabled

Remote Login authentication is enabled when user sets a remote login password using the AT+RLOGIN command. The RLOGIN password should be between 5-16 characters long and have atleast 1 digit. The remote login password can be set only using a serial terminal locally. The remote login password cannot be read or changed remotely over a Bluetooth connection.

For setting remote configuration authentication please see LM048: Remote Configuration of Serial Adapter via Bluetooth Connection

Most of the steps of remote configuration are same as described in the except there is an extra authentication step before the adapter switches to remote configuration mode.

When the handshake sequence 0xAA 0xAA 0xAA 0xAA 0xAA 0xAA 0xAA 0xAA 0x0D is sent to remote adapter, it responds with 0xBB 0xBB instead of 0xBB 0xAA when authentication is disabled. Remote login authentication requests can be handled with LM149 Software v1.6 or above as well as serial terminal. Both these scenarios are described below. Please note the remote login password for below section is LMT1234

Handling Remote Login Authentication Using Serial Terminal

When remote authentication is enabled, the procedure for remote configuration is same as described in section Remote Configuration using Serial Terminal except there is an extra step for remote authentication. The handshake sequence 0xAA 0xAA 0xAA 0xAA 0xAA 0xAA 0xAA 0xAA 0x0D is replied with 0xBB 0xBB. The user has to supply password using command AT+RLOGIN. If password is correct, handshake sequence is complete and user gets OK response. If password is not correct, user gets ERROR response and handshake sequence fails. Please note the AT+RLOGIN response from user is not echoed, so not visible in the serial terminal window. This is shown in the screenshot below.


Once remote authentication is successful and handshake is complete, rest of the procedure to read and change settings is same as described in section Remote Configuration using Serial Terminal.