User's Manual

Table Of Contents
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.
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.
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.
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.
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.
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
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
RX_Active
RX_Active