XStream-PKG-R™ RS-232/485 RF Modem – Product Manual v5.x00
Pin Sle e p ( SM = 1 )
Pin Sleep r equir es t he least am ount of pow er . I n order t o achiev e t his st at e, t he DI 3 ( SLEEP) pin
m ust be asser t ed ( high) . The m odem r em ains in Pin Sleep unt il t he DI 3 pin is de- asser t ed.
Aft er enabling Pin Sleep, t he SLEEP pin cont r ols w het her t he XSt r eam Modem is act ive or in Sleep
Mode. When DI 3 is de- asser t ed ( low ) , t he m odem is fully oper at ional. When DI 3 is asser t ed
( high) , t he m odem t r ansit ions t o Sleep Mode and r em ains in it s lowest pow er - consum ing st at e
unt il t he DI 3 ( SLEEP) pin is de- asser t ed. DI 3 is only act ive if t he m odem is set up t o oper ate in
t his m ode; ot her w ise t he pin is ignor ed.
Once in Pin Sleep Mode, DO2 (
) is de- asser t ed ( high) , indicat ing t hat dat a should not be sent
t o t he m odem . The PWR pin is also de- asser t ed ( low ) w hen t he m odem is in Pin Sleep Mode.
Note: The modem will complete a transmission or reception before activating Pin Sleep.
Se r ia l Por t Sle e p ( SM = 2 )
Ser ial Por t Sleep is a Sleep Mode in w hich t he XSt r eam Modem r uns in a low pow er st at e unt il
ser ial dat a is det ect ed on t he DI pin.
When Ser ial Por t Sleep is enabled, t he m odem goes int o Sleep Mode aft er a user - defined per iod
of inact iv it y ( no t r ansm it t ing or r eceiv ing of dat a) . This per iod of t im e is det erm ined by ST ( Tim e
before Sleep) Com m and. Once a char act er is received t hr ough t he DI pin, t he m odem ret ur ns t o
I dle Mode and is fully oper at ional.
Cy clic Sle e p ( SM = 3 - 8 )
Cy clic Sleep is t he Sleep Mode in w hich t he XStr eam Modem ent er s int o a low - pow er st at e and
aw ak ens per iodically to det erm ine if any t r ansm issions are being sent .
When Cy clic Sleep set t ings are enabled, t he XStr eam Modem goes int o Sleep Mode aft er a user -
defined per iod of inact iv it y ( no t r ansm ission or r ecept ion on t he RF channel) . The user - defined
per iod is det erm ined by ST ( Tim e before Sleep) Com m and.
While t he m odem is in Cyclic Sleep Mode, DO2 (
) is de- asser t ed ( high) t o indicat e t hat dat a
should not be sent t o t he m odem dur ing t his t im e. When t he m odem aw ak ens t o list en for dat a,
DO2 is asser t ed and any dat a r eceiv ed on t he DI Pin is t r ansm it t ed. The PWR pin is also de-
asser t ed ( low ) w hen t he m odem is in Cy clic Sleep Mode.
The m odem rem ains in Sleep Mode for a user - defined per iod of t im e r anging fr om 0.5 seconds t o
16 seconds ( SM Par am et er s 3 t hr ough 8) . Aft er t his int er v al of t im e, t he m odem ret ur ns to I dle
Mode and list ens for a v alid dat a packet for 100 m s. I f t he m odem does not det ect v alid dat a ( on
any fr equency ) , t he m odem ret ur ns t o Sleep Mode. I f v alid dat a is det ect ed, t he m odem
t r ansit ions int o Receiv e Mode and receives incom ing RF pack et s. The m odem t hen r et ur ns t o
Sleep Mode aft er a Per iod of inact iv it y t hat is det er m ined by ST “ Tim e before Sleep” Com m and.
The m odem can also be configur ed t o w ak e fr om cy clic sleep w hen SLEEP/ DI 3 is de- assert ed
( low ) . To configur e a m odem t o oper at e in t his m anner , PW ( Pin Wak e- up) Com m and m ust be
issued. Once DI 3 is de- asser t ed, t he m odem is for ced int o I dle Mode and can begin tr ansm it t ing
or r eceiv ing dat a. I t r em ains act iv e unt il no dat a is det ect ed for t he per iod of t im e specified by
t he ST Com m and, at w hich point it r esum es it s low - pow er cy clic st at e.
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 modem 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”
© 2014 Digi International Inc.
17