Sony SPP-A9171 Service Manual page 20

5. Link Establishment
According to the following Fig. 3-1, the requested side for link
establishment is the master.
The system have to exchange the A-Frame for link establishment,
and each system ID should be the same ID, and then the system link
is established.
The protocol and timing chart of link establishment are as follows.
Master
Time Slot
A
Master TX
Master RX
Slave RX
Slave TX
Trip Delay
6. State Change/Tarmination
After the RF link between HANDSET and BASE UNIT was
established, a movement of each state (State: ON-Hook, OFF-Hook,
PAGE, Intercom, etc) is sent through supervisory bits.
7. Error Recovery
In case of the following situation, The system becomes "Error
Recovery Mode".
(1) The system failed to move to "Heart-Beat" during "Stand-by
mode, or failed "link establishment".
(2) The system failed to keep the link.
TX RX
A'
A
A'
Fig. 3-4. Link Establishment Timing Chart
Master
System ID
confirmed
Fig. 3-3. Link Establishment protocol
TX
V
V
— 20 —
Slave
A-Frame
A-Frame
V-Frame
V-Frame
V-Frame
V-Frame
RX TX
V
V
V
V
System ID
confirmed
V