Technical Manual

42
Wireless Sensor Interface A720 (addIT™)
• RSET – sets remotely certain parameters (id, frequency, slot, power manage-
ment parameters).
Note: RSETIO frame is provided only for backwards compatibility with the A730MD. Better ways
to control the ports will be implemented at a later date.
The device will not recognize a broadcast frame and will not answer to such frames.
It will however send a broadcast and wait for answers in the Connectivity Check Mode,
or if a Broadcast command is issued at the terminal. Even if the device is not intended
to be used as a router, the current software version implements routing; due to power
consumption reasons, this mode of operation is not recommended.
Figure 26. State Transition Diagram of the radio communication task.
4.5.1. Digital Squelch
In order to reduce the power consumption during receive mode, the unit uses a pro-
tocol developed by Adcon Telemetry for the A730 family, but with some additional
refinements to further reduce the power consumption. The receiver is pulsed at a 0.5
seconds interval. At wake-up, the receiver samples first the RF channel for a carrier,
by measuring the RSSI. The RSSI output is extremely stable due to the wide dynamic
range that the IF chip exhibits (over 100 dB, temperature compensated). If the sam-
Idle
Measure RF
Check
Destination
No Signal
0.5 sec
Interrupt
Header Detected
Not for us
Get Frame
We are called
New Frame Possible
Wait
Nhops + 1 s
and
Measure RF
Timeout Expired
Etc.
Answer
Appropriately
Send
Pong
Ping
Request
Send
Answer
and Wait
for Ack
Ack
Ack
Ack
Resend
Frame with
Long
Header
Frame Sent Twice
No Ack
No Ack
No Ack