HBM PACEline CMD600 - Discovery Procedure

9
CMD600
A2820−1.1 en
4 Discovery procedure
When measurement application does not know the IP address of charge
amplifier it can send UDP broadcast discovery packet. It should use Ethernet
broadcast address (ff:ff:ff:ff:ff:ff) and IP broadcast address (ff.ff.ff.ff). The
destination port should be 85 and source port should be 86. The packet
should have 4 data bytes : 0x77, 0x68, 0x65, 0x72.
The whole discovery packet capture is shown on Figure Fig. 2.
Fig. 2: Discovery packet capture
After reception of discovery packet all charge amplifier on the network starts
to send discovery response packet. Discovery response packet is unicast
UDP packet with destination IP address of discovery sender and source IP
address of the amplifier. Source port is 85 and destination port is 86.
Within discovery response packet there is additional information (26 bytes)
about amplifier:
• Amplifier IP
• Device ID
• Device description
Example of discovery response data definition.
unsigned char deviceDesc[26] =
{
10,60,250,143,
// textual representation of IP address (4 bytes)
ff, 35, a1, 0, 0, 1,
// textual representation of amplifier ID(6 bytes)
’E’, ’m’,’s’,’i’,’s’,’o’,’ ’,’c’,’h’,’a’,’r’,’g’,’e’,’0’,’1’,
// Device descriptiom (15 bytes)
0
// end of discovery response packet
};