Digi radio modems perform a 16-bit CRC (cyclic redundancy check) to check for errors in every transmitted data packet. If an error is found the packet is discarded and not sent out the serial port.
Error correction is available on the XStream and XTend families of radio modems in the form of Packet Acknowledgements and Retries, also known as Reliable Delivery mode. Reliable Delivery mode is enabled by setting ''ATRR'' to a nonzero value. ''ATRR'' is a software parameter internal to the radio module. In the event of a communication failure the transmitting modem will resend the data packet up to RR times. Max. value of RR is 0xFF (255 decimal), default is 0 (no retries). This ability provides a powerful solution for error correction without any additional cost; the Retries feature is built into each radio modem.
For more on reliable delivery, visit Configuring the modems for reliable delivery.
Data packet sizes can be as large as 64 bytes (this value is adjustable up to 256 bytes in beta firmware versions). For more information visit MaxStream's packetizing algorithm.