Packet Handler Rx - Semtech SX1211SK User Manual

6.6

PACKET HANDLER RX

The Packet Handler Rx window is displays below.
A
A: Sync size: Uses to set the length of the synchronisation word, from 1 byte to 4 bytes.
a : The value can be modified in the Sync-value window.
B: Sync-tol: Uses to set the tolerance on the reception. Number of errors accepted
C: Pkt_format: Uses to program the packet format. If the selected format is "variable", the length of the
payload entered in the window is the maximum length of the message. If the message received is
longer than the programmed payload length, the message is discarded.
c : Payload length: Length of the payload must be entered manually for the Fixed and Variable option.
D: Adrs_filt: Address filtering adds another level of filtering above Sync-word.
Three address filtering options are implemented:
•
Node_adrs: Received address filed is compared with Node_adrs register (d),
if they match the packet is accepted and processed else it is discarded.
•
Node_adrs +0x00: Received address filed is compared with Node_adrs
register (d) and the constant 0x00. If any of the two matches, the received
packet is accepted and processed, else it is discarded.
•
Node_adrs +0x00 +0xFF: Received address filed is compared with
Node_adrs register (d) and constants 0x00 and 0xFF. If any of the three
matches, the received packet is accepted and processed, else it is discarded.
d : Node_adrs register, uses to compare with the received address.
E: CRC: The CRC is used for checking the integrity of the message. The status is display thanks to a
LED on the screen called CRC_status.
F: DC Free Encoding: Two methods of en coding are available with the SX1211, the Manchester
encoding and the Withering encoding. For more information, please refer to the Semtech SX1211
Datasheet.
G: Fifo_size: The Fifo-size can not be modified and is hard-coded to 64bytes.
Rev1.1
SX1211SK868/915 User Guide
B C
a c
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D E
d
F G
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