Product manual

XStream‐PKG‐T™TelephoneRFModem–ProductManualv5.x00[2006.02.24]

The module remains in Sleep Mode for a user-defined period of time ranging from 0.5 seconds to

16 seconds (SM Parameters 3 through 8). After this interval of time, the module returns to Idle

Mode and listens for a valid data packet for 100 ms. If the module does not detect valid data (on

any frequency), the module returns to Sleep Mode. If valid data is detected, the module

transitions into Receive Mode and receives incoming RF packets. The module then returns to

Sleep Mode after a Period of inactivity that is determined by ST “Time before Sleep” Command.

The module can also be configured to wake from cyclic sleep when DI3 (SLEEP) is de-asserted

(low). To configure a module to operate in this manner, PW (Pin Wake-up) Command must be

issued. Once DI3 is de-asserted, the module is forced into Idle Mode and can begin transmitting

or receiving data. It remains active until no data is detected for the period of time specified by

the ST Command, at which point it resumes its low-power cyclic state.

Note: The cyclic interval time defined by SM (Sleep Mode) Command must be shorter than the interval

time defined by LH (Wake-up Initializer Timer).

For example: If SM=4 (Cyclic 1.0 second sleep), the LH Parameter should equal 0x0B (“1.1” seconds).

With these parameters set, there is no risk of the receiving module being asleep for the duration of

wake-up initializer transmission. “Cyclic Scanning” explains in further detail the relationship between

“Cyclic Sleep” and “Wake-up Initializer Timer”

Cyclic Scanning. Each RF transmission consists of an RF Initializer and payload. The wake-up

initializer contains initialization information and all receiving modules must wake during the

wake-up initializer portion of data transmission in order to be synchronized with the transmitting

module and receive the data.

Figure2‐06. CorrectConfiguration(LH>SM):

Lengthofthewake‐upinitializerexceedsthetimeintervalofCyclicSleep.Thereceiverisguaranteedtodetect

thewake‐upinitializerandreceivetheaccompanyingpayloaddata.

Figure2‐07. IncorrectConfiguration(LH<SM):

Lengthofwake‐upinitializerisshorterthanthetimeintervalofCyclicSleep.Thisconfigurationisvulnerable

tothereceiverwakingandmissingthewake‐upinitializer(andthereforealsotheaccompanyingpayloaddata).

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