User's Manual

Radio Operation
Crescendo VHF Half-Duplex User Manual Page 23 of 74
Link quality: The quality of a link can have a substantial impact on the latency induced by the
radio. The Crescendo will retry packets that become corrupted due to RF interference, configurable
between 0 and 20 retries. The more retries that are required to successfully transmit a packet, the
greater the latency induced. This is only applicable to packet driven mode.
Multiple protocols: When multiple protocols are used (including management with Cruise Control),
latency will be increased as extra protocol data is inserted into the data stream.
Repeaters: The addition of repeaters in a network will increase latency due to payload packets and
acknowledgements being transmitted multiple times before reaching their destination.
For systems that require low latency, the Crescendo has a data driven protocol which reduces many of the
delays mention above.
5.3 Radio Parameters
5.3.1 Addressing
Each radio in a Crescendo network has a unique 16-bit address. The address space is divided into sections as
shown in Table 9.
Address Range
Usage
0
Reserved.
1 – 61439
Singlecast addresses.
Each radio in a network must have a unique singlecast address.
61440 – 65534
Reserved.
These addresses are reserved for use in future Crescendo releases.
65535
Broadcast address.
This address is used when data transmitted is to be processed by all
radios. This address can only be used in the datagram packet header
Table 9: Crescendo address space
The singlecast radio address is used for routing traffic between units and determining the end points in a
communications link.
Only one singlecast address can be assigned to each radio, and each radio in a particular network must have
a unique address.
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