The device is intended for installation on railway carriages (or other vehicles without power supply) to provide the position and motion data remotely and automatically, using GPRS / SMS services of public GSM networks. The unit has its own power source for 12..36 months. It is encapsulated in the rigid (IK09), hermetic (IP67) polycarbonate/ABS enclosure. The device is intended to conform to the ATEX safety requirements.
The main task of the device is to periodically and reliably transmit the data, containing:
- Position (or any other data available from GPS),
- State of the vehicle (in motion or steady),
- Power status.
The capacity of battery used ensures an adequate supply of energy for selected activities of the device. Operating mode (period / type of transmission) is a remotely configurable function. The device is equipped with a data buffer to allow for local data storage in case of temporary unavailability of GSM infrastructure. The size of the buffer allows for the acquisition of data records up to 1 month. The device is equipped with a wireless RFID interface, which allows easy management of monitored fleet vehicles - each vehicle / carriage may have its own, fixed ID and every device is able to read this identifier.
The whole device consists of two parts: radio unit and control unit. The radio unit consists of a GPS module, GSM module and a socket for optional, future Low Power Radio module. The radio unit can be supplied from the control unit, or may be treated as a separate and independent development, which may be easily attached to different control devices. Both the GPS and GSM modules can be selectively turned no or off.
The control unit is based on a low-power Energy Micro processor. Thanks to its energy efficiency, the current consumption in sleep mode drops to only 80uA in GPS standby mode. The entire control unit also includes modules such as:
- RFID reader,
- current measurement subsystem,
- battery state measurement subsystem,
- 3-axis accelerometer + temperature sensor,
- two external FLASH memories,
- external EEPROM memory,
- two motion sensors.
Internal architecture of the unit allows for selective powering of all peripherals. This gives the ability to precisely control the system to reduce the current consumption during the wake up time.