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10
Communication
All the features below are implemented in a demonstration program available from
www.gardasoft.com.
10.1.1
Automatic Sensing
The PP420 will send out a message on three events:
•
On power up
•
When an IP address is received or renewed by DHCP
•
When an enquiry message is received
On the first two events, the message is broadcast. On the third it is a reply to a single IP address.
An enquiry message is a UDP packet from source port 30310, destination port 30311 with the
message body “Gardasoft Search” (8-bit ASCII, 13 characters).
The message output by the PP420 is a UDP packet from source port 30311, destination port
30310. It is formatted as:
Gardasoft,PP420,000000,111111111111,22222222
(8-bit ASCII, 44 characters), where
000000
the serial number of the unit
111111111111
the MAC address in 6 HEX bytes
22222222
the IP address in 4 HEX bytes
For example for PP420 serial number 12345, IP address 192.168.1.103, MAC address
00.0B.75.01.80.99 the packet will contain
Gardasoft,PP420,012345,000B75018099,C0A80167