XIB-R Digi International/Maxstream, XIB-R Datasheet - Page 13

• Manufacturer Part Number: XIB-R
• Description: BOARD INTERFACE RS232/485
• Manufacturer: Digi International/Maxstream

Specifications of XIB-R

• Accessory Type: Interface Board
• For Use With/related Products: XStream and Xcite Radios
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: Q2231853

9XCite™ OEM RF Module – Product Manual v2.1 [2007.01.04]
Serial Port Sleep (SM = 2)
Serial Port Sleep is a Sleep Mode setting in which the modem runs in a low power state until data
is detected on the DI pin.
When Serial Port Sleep is enabled, the modem goes into Sleep Mode after a user-defined period of
inactivity (no transmitting or receiving of data). This period of time is determined by ST (Time
before Sleep) Command. The modem returns to Idle Mode once a character is received through
the DI pin.
Cyclic Sleep (SM = 3-8)
Cyclic Sleep is the Sleep Mode setting in which the XCite Module enters into a low power state and
awakens periodically to determine if any transmissions are being sent.
When Cyclic Sleep settings are enabled, the XCite Module goes into Sleep Mode after a user-
defined period of inactivity (no transmission or reception on the RF channel). The user-defined
period is determined by ST Parameter. [See ST (Time before Sleep) Parameter]
While the modem is in a low-power state, CTS de-asserted (high) to indicate that data should not
be sent to the modem during this time. When the modem awakens to listen for data, CTS is
asserted and any data received on the DI Pin is transmitted. The PWR pin is also de-asserted (low)
when the modem is in Cyclic Sleep Mode. These pins are asserted each time the modem cycles
into Idle Mode to listen for valid data packets and de-asserts when the modem returns to Sleep
Mode.
The modem 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 modem returns to Idle
Mode and listens for a valid data packet for 100 ms. If the modem does not detect valid data (on
any frequency), the modem returns to Sleep Mode. If valid data is detected, the modem transi-
tions into Receive Mode and receives the incoming packets. The modem then returns to Sleep
Mode after a Period of inactivity that is determined by ST "Time before Sleep" Parameter.
The modem can also be configured to Wake-up from cyclic sleep when the SLEEP pin is de-
asserted (low). To configure a modem to operate in this manner, PW (Pin Wake-up) Command
must be issued. Once the Sleep pin is de-asserted, the modem 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 parameter, 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") Command. For example: If SM=4 (Cyclic 1.0 second
sleep), the LH Parameter should equal 0xB ("1.1" seconds). With these parameters set, there is no risk
of the receiving modem being asleep for the duration of the wake-up initializer transmission. The fol-
lowing section "Cyclic Scanning" explains in further detail the relationship between "Cyclic Sleep" and
"Wake-up Initializer Timer"
Cyclic Scanning. Each RF transmission consists of a wake-up initializer and payload data. The
wake-up initializer contains initialization information and all receiving modems must Wake-up dur-
ing the wake-up initializer portion of data transmission in order to synchronize with the transmitter
and receive the data.
The cyclic interval time defined by the SM (Sleep Mode) command must be shorter than the interval
time defined by LH (Wake-up Initializer Timer) command.
Figure 2‐07. Correct Configuration (LH > SM):
© 2007 MaxStream, Inc.
• Wake on serial port activity
The 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.
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