User's Manual

Sent Data:

Group Data

into Packets:

Figure 5a – Transmit Mode description. Figure 5b – Generation of data packets.

Data Validity

To verify data integrity, a 16-bit cyclic redundancy check (CRC) is computed for the transmitted

data and attached to the end of each data packet before transmission. The receiver will then

compute the CRC on all incoming data. Any received data that has an invalid CRC is discarded.

Transmission Latency

The time required to send a packet of data depends on the number of bytes being sent, and the

baud rate. In addition, the modules have a synchronization timer option that can be manually

configured using the SY command as discussed in the “24XStream Command Table”. Modifying

this parameter can significantly change the transmission latency. See the “Timing Diagrams”

section for more information on transmission latencies.

A Note About Headers

As noted in Figure 5, data packets are always prefaced by a header. The header contains

information that is used by all receivers (within range) to synchronize their hopping patterns to

the transmitter. The length of the header can be reduced in some applications by eliminating the

synchronization information. See “Timing Diagrams” for more information.

Receive Mode

If over-the-air data is present at the RF receiver when the module is in Idle Mode, it will

transition to Receive Mode and start receiving packets. Once a packet is received, it goes through

a CRC (cyclic redundancy check) to ensure that the data was transmitted correctly. If the CRC

data bits on the incoming packet are invalid, the packet is discarded. If the CRC is valid, the

packet is sent to the serial port via the DO pin. This process is shown in Figure 6 below.