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Modes of operation
9XTend-PKG-R RS-232/485 RF Modem User Guide
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The modem returns to Idle Mode when valid RF data is no longer detected or after an error is detected in the received
RF data. If serial data is stored in the DI buffer while the modem is in Receive Mode, the serial data will be transmitted
after the modem is finished receiving data and returns to Idle Mode.
Sleep mode
Software sleep
Sleep Modes enable the modem to enter states of low-power consumption when not in use. Three software Sleep
Modes are supported:
•
Pin Sleep (Host Controlled)
•
Serial Port Sleep (Wake on Serial Port activity)
•
Cyclic Sleep (Wake on RF activity)
In order to enter Sleep Mode, one of the following conditions must be met (in addition to the modem having a non-
zero SM parameter value):
1. The modem is idle (no data transmission or reception) for the amount of time defined by the ST (Time before
Sleep) parameter.
Note
ST is only active when SM = 4-5.
2. GPI2 (SLEEP) is asserted (only for the ‘Pin Sleep’ option).
When in Sleep Mode, the modem will not transmit or receive data until the modem first transitions to Idle Mode. All
Sleep Modes are enabled and disabled using SM Command. Transitions into and out of Sleep Modes are triggered by
various mechanisms as shown in the table below.
Sleep Mode
(Setting)
Transition into
Sleep Mode
Transition out of Sleep Mode
(wake)
Related
Commands
Power
Consumption
Pin Sleep
(SM = 1)
Assert GPI2 pin - A micro controller can
shut down and wake modems via the
GPI2 pin.
Note: The modem will complete a
transmission or reception before
activating Pin Sleep.
De-assert GPI2 pin
(SM)
See
Serial Port Sleep
(SM = 2)
Automatic transition to Sleep Mode
occurs after a user-defined period of
inactivity (no transmitting or receiving
of data).
Period of inactivity is defined by the ST
(Time before Sleep) Command.
When a serial byte is received on
the DI pin
(SM), ST
Cyclic Sleep
(SM = 4 - 8)
RF modem transitions in and out of Sleep Mode in cycles (user-selectable
wake-up interval of time is set using the SM command). The cyclic sleep
interval of time must be shorter than the interval of time that is defined by
the LH (Wake-up Initializer Timer) command.
Note: The modem can be forced into Idle Mode using the GPI2 pin if the PW
(Pin Wake-up) command is issued.
(SM), ST, HT,
LH, PW