GPB-312 Bluetooth Optical ProbeBluetooth Optical Probe (GPB 312) which conforms to the IEC62056 21(DLMS) Bluetooth standard. Using Bluetooth wireless communication technology, it can replace the existing optical probe cables to realize wireless data communication. It applies to read and write domestic and foreign smart meters which conform to IEC standard, can read data from DLMS energy meter. It supports BLE mode; connects to computer, mobile phone. The maximum communication range