Protocol Operation
Crescendo VHF Half-Duplex User Manual
Page 40 of 74
Start
0xC1
Destination
0x0001
Source
0x0000
CRC
0x9496D61C
Data
0x54 0x45 0x53 0x54
DP / SP / Res
0x00
Length
0x0009
Figure 11: Example datagram protocol packet
Datagram protocol applications are given in section 7.4.
6.9 RF Link Status
The Crescendo provides an RF link status indication for each serial port. The RF link status depends on the
protocol mode being used and the current state of that protocol. The meaning of different RF link status
values is provided in Table 15 for each protocol mode.
Protocol
State
RF Link Status
Point-to-point
Connection Based
Connected if a path exists between the
local and remote device. Not Connected
if there is no communications path.
Connectionless
N/A
Point-to-multipoint
N/A
Hayes dial-up
Connection
established
Connected if a path exists between the
local and remote device. Not Connected
if there is no communications path.
No connection
established
Not Connected
Datagram
N/A
Table 15: RF link status for different protocol modes
Whenever the protocol mode on a serial port is temporarily disabled (such as when the menu is enabled on
the port, or when the Cruise Control application has been started), the RF Link Status will be displayed as
N/A.
6.10 Protocol to Radio Address Mapping
Protocol address mapping can be used in situations where the radio address is not the same as the protocol
address, or where there is more than one protocol address for each radio address. A protocol mapping entry
has each of the following fields:
First Addr:
The first protocol address to apply to the protocol mapping.
Last Addr:
The last protocol address to apply to the protocol mapping.
Radio Addr:
The radio address to apply to the protocol mapping.
Type:
A protocol mapping entry can be one of four types:
Main -> Protocol
Main -> Protocol