The 250 Series RF transceiver module is designed for reliable bi-directional transfer of digital data over distances of up to 4 miles (6.4km), line of sight. Operating in the 902 to 928 MHz ISM (Industrial Scientific and Medical) frequency band, the module is capable of generating +23.5 dBm into a 50-ohm load and achieves an outstanding typical sensitivity of –105 dBm. This high output power gives the module exceptional range and also helps overcome noisy environments at shorter ranges. Regulations in the country of operation dictate the maximum legal output power, so the final system range may be less depending on the country of operation.
The 250 Series module implements a Frequency Hopping Spread Spectrum (FHSS) protocol along with networking and assured delivery features. It has a Universal Asynchronous Receiver Transmitter (UART) serial interface that can be connected directly to microcontrollers, RS-232, RS-485 converters or USB adaptors. The module automatically handles all radio functions resulting in a UART-to-antenna wireless link.
The transceiver has a robust built-in protocol. A carrier sense multiple access (CSMA) algorithm assures the channel is clear before sending data. Networking and assured delivery enable many system configurations. The transceiver contains several registers, accessed through the UART, that control its configuration and operation.
Low power modes as well as adjustable transmitter output power allow the designer to optimize the current consumption for the available power supply in the application. Compared to XBEE and WIT900 products, current consumption on both the transmit side and receive side is significantly less; as low as 25% of these products’ current requirements. In addition, the 250 Series Transceiver is a lower cost solution to other similar products, such as XBEE or WIT910.
Common applications for the 250 Series transceiver module that require reliable long range digital date transfer include long range data links, wireless sensors, asset tracking, automated meter reading, industrial automation as well as home automation.
An evaluation module is available that has the module on a board with an antenna connector and voltage regulator. There are variants with United States FCC, Industry Canada, and Mexico COFETEL certifications. This greatly reduces the expense and time to implement a wireless solution.