User's Manual

MaxStream 9XStream™ Wireless OEM Module Manual v2.8
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Confidential and Proprietary, ©MaxStream, Inc. 2001
Figure 7a – The length of
the long header is not as
long as the period of
Cyclic Sleep. It is possible
for the receiver to wake
and miss the header (and
the data packet) in this
scenario.
Figure 7b – The length of the
long header exceeds the
period of Cyclic Sleep. The
receiver is guaranteed to
detect and receive the data
packet.
The long header is only sent with the initial transmitted packet after a user-
defined period of inactivity (no serial data received and no over-the-air
transmitting or receiving). This period of inactivity must be adjusted using the
HT command as described in the 9XStream Commands Table (Appendix E).
Sending a long header assures that the receiver will detect the new transmission
and will be able to receive the data (as long as the header length slightly exceeds
the cyclic sleep time).
Command Mode
Command Mode allows several features, including the power-down and
addressing options, to be configured. These adjustable parameters offer greater
flexibility to designers in configuring the module to fit specific design criteria.
There are three ways to enter Command Mode:
1. Assert RTS/CMD and send a binary command.
2. Send the sequence “+++” to send AT commands.
3. Assert (low) the CONFIG pin and turn the power switch off and back on.
Important: Do not tie CONFIG pin to microprocessor. (See the
Serial Port Operation section for more information.)
Once in Command Mode, the configurable parameters can be adjusted using
either AT commands or Binary commands, as explained below. Any parameters
that are changed while in Command Mode must be saved to non-volatile
memory using the WR command, or they will reset to their stored value upon
reset or power-up.