Point Six Link Manager 4010-43, Руководство пользователя, Страница: 30 / 131

28

Development Notes Link Manager Manual
Development Notes
Overview
The Link Manager follows the “Extended Point Sensor Packet Specification”. If you
have written an interface for Wifi Point Sensor, then the Link Manager will work
with your interface. There are two features that you will want your interface to take
advantage of the details that differs from using the Wifi Point Sensor:
1. When the Link Manager recollects the whole sensor buffer, it will set the
“Link Manager recollected sensor’s buffer” bit in the “status2” byte in the
beacon packet. The Link Manager collects the whole sensor buffer under
the following conditions:
a. First time collecting the sensor data.
b. If the current sensor clock is less than the previous sensor clock
value. This can happen when the sensor’s log buffer is cleared.
c. If the sensor has been offline for the time it takes to fill the log
buffer to 3/4s full (logging at 2 mins, this is 3 days).
2.
The “org” – origin value in the beacon packet is set to 7 to indicate the data
came from a Link Manager
3.
The Mac field in the beacon packet is set to the Link Manager’s MAC
address.
“I Am Here Packet”
Link Managers will transmit an “I am here” UDP packet to the host when the Link
Manager has not sent a UDP packet on behalf of a sensor for more than 5 minutes. If
no sensors are registered, the Link Manager will send the “I am here” packet every
30 minutes. The Link Manager sends the Cmd 5 which is the same command as the
Point Sensor Utility sends for the Contact Destination packet. The Link Manager
sets the MAC field to its MAC address and sets the “org” field to 7. All other fields
are set to 0.