X24-009PKC-UA Digi International/Maxstream, X24-009PKC-UA Datasheet - Page 9

• Manufacturer Part Number: X24-009PKC-UA
• Description: MODEM RF 2.4GHZ 9600BPS USB
• Manufacturer: Digi International/Maxstream
• Series: XStream™r

Specifications of X24-009PKC-UA

• Function: Transceiver, Modem
• Modulation Or Protocol: FHSS
• Frequency: 2.4GHz ~ 2.4835GHz
• Applications: General Purpose
• Interface: USB
• Sensitivity: -110dBm
• Power - Output: 17dBm (50mW)
• Data Rate - Maximum: 20 kbps
• Voltage - Supply: 5V
• Package / Case: Module
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification
• Features: -

XStream‐PKG‐U™ USB RF Modem – Product Manual v4.2B5 [2006.02.27]
2.2. Modes of Operation
2.2.1. Idle Mode
2.2.2. Transmit Mode
An on-board RF module enables the XStream-PKG-U RF Modem to send and receive data over-
the-air. The RF module operates in five modes.
Figure 2‐01. RF Modem Modes of Operation
The RF modem can only be in one mode at a time.
When not receiving or transmitting data, the RF modem is in Idle Mode. The RF modem uses the
same amount of power in Idle Mode as it does in Receive Mode.
The modem shifts into the other modes of operation under the following conditions:
After responding to any of the preceding conditions, the modem automatically transitions back
into Idle Mode.
When the first byte of serial data is received from the UART in the DI buffer, the modem
attempts to shift to Transmit Mode and initiate an RF connection with other modems.
Figure 2‐02. Transmission of Data
Once in Transmit Mode, the modem
initializes a communications
channel. Channel initialization is the
process of sending an RF initializer
that synchronizes receiving modems
with the transmitting modem. When
streaming multiple RF packets, the
RF Initializer is only sent in front of
the first packet. During channel
initialization, incoming serial data
accumulates in the DI buffer.
After the channel is initialized, data
in the DI buffer is grouped into
packets (up to 64 bytes in each
packet) and is transmitted. The
modem continues to transmit data
packets until the DI buffer is empty. Once transmission is finished, the modem returns to Idle
Mode. This progression is shown above.
As the transmitting modem nears the end of the transmission, it inspects the DI buffer to see if
more data exists to be transmitted. This could be the case if more bytes arrived from the host
after the transmission began. If more data is pending, the transmitting modem assembles a
subsequent packet for transmission.
© 2006 MaxStream, Inc. Confidential and Proprietary
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Serial data is received in the DI Buffer (Transmit Mode)
Valid RF data is received through the antenna (Receive Mode)
Command Mode Sequence is issued (Command Mode)
Sleep Mode condition is met (Sleep Mode)
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