Itron 0001 ユーザーズマニュアル
4-12
July 23, 2002
Hardware Integration
CreataLink2 XT Hardware Integrator’s Guide
Host Interface
There are two scenarios resulting from the use of the battery save cycle. See Figure
4-10 illustrating the state of the RX_Active signal and receiver powerup state.
4-10 illustrating the state of the RX_Active signal and receiver powerup state.
Scenario 1:
The data transceiver powers up its receiver and there is no message being delivered.
In this case, the receiver will only be powered up for a small part of the entire frame.
In this case, the receiver will only be powered up for a small part of the entire frame.
Scenario 2:
The data transceiver powers up its receiver and a message is being delivered. In
this case, the receiver is left powered up long enough to receive the message.
this case, the receiver is left powered up long enough to receive the message.
A third, but unrelated, scenario which causes the receiver to be powered up is the
initiation of a transmission. The ReFLEX protocol requires that the data transceiver
be receiving at the start of the frame where a transmission will occur to ensure
synchronization to the system before it transmits. In this case, even if the data
transceiver is operating with a collapse of 3 where the data transceiver only wakes
up every 8 frames, the receiver will be powered up before a transmission.
initiation of a transmission. The ReFLEX protocol requires that the data transceiver
be receiving at the start of the frame where a transmission will occur to ensure
synchronization to the system before it transmits. In this case, even if the data
transceiver is operating with a collapse of 3 where the data transceiver only wakes
up every 8 frames, the receiver will be powered up before a transmission.
The behavior of the TX_ACTIVE line is similar. When the data transceiver is
actively transmitting a message, the TX_Active signal is activated. When the
transmission subsequently completes, the TX_Active signal is deactivated.
actively transmitting a message, the TX_Active signal is activated. When the
transmission subsequently completes, the TX_Active signal is deactivated.
Figure 4-10. Behavior of Receiver Active Line. Assumes collapse is 1 (Wake up every other frame)
Frame 1
Frame 2
Frame 3
Frame 4
Behavior of Receiver Active line. Assumes collapse is
Scenario 1-Wake up, Look for message, and go back to sleep
Scenario 2. Wake up, Receive message in Frame 1, and go back to
sleep
sleep
RX_Active
RX_Active