9XTend
‐
PKG
‐
E™
Ethernet
RF
Modem
–
Product
Manual
v2.x4x
[2007.01.04]
©
2007
MaxStream,
Inc.,
Confidential
&
Proprietary
‐
All
Rights
Reserved
17
The SM ( Sleep Mode) com m and is cent ral t o set t ing all Sleep Mode configurat ions. By default ,
Sleep Modes are disabled ( SM = 0) and t he m odem rem ains in I dle/ Receive Mode. When in t his
st at e, t he m odem r em ains const ant ly r eady t o respond t o serial or RF act ivit y.
Se r ia l Por t Sle e p ( SM = 2 )
• Wake on serial port act ivit y
• Typical pow er- dow n current : < 210 m A
Serial Port Sleep is a Sleep Mode in w hich t he m odem r uns in a low pow er st at e unt il serial dat a is
det ect ed on t he DI pin.
The period of t im e t he m odem sleeps is det erm ined by ST ( Tim e before Sleep) Com m and. Once a
charact er is r eceived t hr ough t he DI pin, t he m odem ret urns t o I dle Mode and is fully operat ional.
Cy clic Sle e p ( SM = 4 - 8 )
• Typical Pow er- dow n Cur r ent : < 210 - 224 m A ( w hen asleep)
Cyclic Sleep Modes allow m odem s t o periodically wake and check for RF dat a. The m odem wakes
according t o t he t im es designat ed by t he Cyclic sleep set t ings. I f t he m odem det ect s a wake- up
init ializer during t he t im e it is awake, t he m odem synchronizes wit h t he t ransm it t ing m odem and
r eceives dat a aft er t he wake- up init ializer r uns it s durat ion. Ot herw ise, t he m odem ret urns t o
Sleep Mode and cont inues t o cycle in and out of act ivit y unt il a wake- up init ializer is det ect ed.
While t he m odem is in Cyclic Sleep Mode, CTS ( GPO1) is de- assert ed ( high) t o indicat e t hat dat a
should not be sent t o t he m odem . When t he m odem awakens t o list en for dat a, GPO1 is assert ed
and any dat a received on t he DI Pin is t ransm it t ed. The PWR pin is also de- assert ed ( low ) w hen
t he m odem is in Cyclic Sleep Mode.
The m odem rem ains in Sleep Mode for a user- defined period of t im e ranging from 0.5 seconds t o
16 seconds ( SM param et ers 4 t hrough 8) . Aft er t his int erval of t im e, t he m odem ret urns t o I dle
Mode and list ens for a valid dat a packet for 100 m s. I f t he m odem does not det ect valid dat a ( on
any frequency) , t he m odem ret urns t o Sleep Mode. I f valid dat a is det ect ed, t he m odem t ransi-
t ions int o Receive Mode and r eceives t he incom ing RF packet s. The m odem t hen r et ur ns t o Sleep
Mode aft er a period of inact ivit y det erm ined by t he ST " Tim e before Sleep" param et er.
The m odem can also be configured t o wake from cyclic sleep w hen t he SLEEP pin is de- asser t ed.
To configure a m odem t o operat e in t his m anner, PW ( Pin Wake- up) Com m and m ust be issued.
Once t he SLEEP pin is de- assert ed, t he m odem is forced int o I dle Mode and can begin t ransm it t ing
or receiving dat a. I t rem ains act ive unt il dat a is no longer 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 resum es it s low- power cyclic st at e.
Cy clic Sca n n in g
. Each RF t ransm ission consist s of an RF I nit ializer and payload. The RF init ializer
cont ains init ializat ion inform at ion and all receiving m odem s m ust wake during t he wake- up init ial-
izer port ion of dat a t ransm ission in order t o be synchr onized w it h t he t ransm it t ing m odem and
r eceive t he dat a.
The cyclic interval time defined by SM (Sleep Mode) Command must be shorter than the interval time
defined by LH (Wake-up Initializer Timer).
