X24-009PKC-UA Digi International/Maxstream, X24-009PKC-UA Datasheet - Page 10

• 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]
RF Packet
The RF packet is the sequence of data used for communicating information between MaxStream
Modems. An RF Packet consists of an RF Initializer and RF Data.
Figure 2‐03. RF Packet Components
* When streaming multiple RF packets, the RF Initializer is only sent in front of the first packet.
RF Initializer
An RF initializer is sent each time a new connection sequence begins. The RF initializer contains
channel information that notifies receiving modems of information such as the hopping pattern
used by the transmitting modem. The first transmission always sends an RF initializer.
An RF initializer can be of various lengths depending on the amount of time determined to be
required to prepare a receiving modem. For example, a wake-up initializer is a type of RF
initializer used to wake remote modems from Sleep Mode (Refer to the FH, LH, HT and SM
Commands for more information). The length of the wake-up initializer should be longer than the
length of time remote modems are in cyclic sleep.
Header
The header contains network addressing information that is used to filter incoming RF data. The
receiving modem checks for matching a VID, Hopping Channel and Destination Address. Data
that does not pass through all three network filter layers is discarded.
Figure 2‐04. Network Layers Contained in the Header
CRC (Cyclic Redundancy Check)
To verify data integrity and provide built-in error checking, a 16-bit CRC (Cyclic Redundancy
Check) is computed for the transmitted data and attached to the end of each RF packet. On the
receiving end, the receiving modem computes the CRC on all incoming RF data. Received data
that has an invalid CRC is discarded [Refer to Receive Mode section].
© 2006 MaxStream, Inc. Confidential and Proprietary
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