A24-HASM-450 Digi International/Maxstream, A24-HASM-450 Datasheet - Page 10

• Manufacturer Part Number: A24-HASM-450
• Description: ANT 2.4GHZ DIPOLE HALF-WAVE
• Manufacturer: Digi International/Maxstream
• Series: XPressr

Specifications of A24-HASM-450

• Antenna Type: Whip: 1/2 Wave, Swivel, Tilt (Right Angle)
• Number Of Bands: 1
• Frequency: 2.4GHz
• Vswr: 2
• Gain: 2.1dBi
• Termination: RP-SMA
• Mounting Type: Connector
• Height (max): 4.35" (110.5mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 70000340; Q2724499B

XBee/XBee‐PRO OEM RF Modules ‐ ZigBee ‐ v1.x1x [2007.06.01]
Transmit
Serial Transmit Buffer
Receive
Buffer
Buffer
Serial
Serial
Hardware Flow Control (CTS). When the serial receive buffer is 17 bytes away from being full,
by default, the module de-asserts CTS (high) to signal to the host device to stop sending data
[refer to D7 (DIO7 Configuration) parameter]. CTS is re-asserted after the serial receive buffer
has 34 bytes of memory available.
Cases in which the serial receive buffer may become full and possibly overflow:
When RF data is received, the data is moved into the serial transmit buffer and is sent out the
serial port. If the serial transmit buffer becomes full enough such that all data in a received RF
packet won’t fit in the serial transmit buffer, the entire RF data packet is dropped.
Hardware Flow Control (RTS). If RTS is enabled for flow control (D6 (DIO6 Configuration)
Parameter = 1), data will not be sent out the serial transmit buffer as long as RTS (pin 16) is de-
asserted.
Cases in which the serial transmit buffer may become full resulting in dropped RF
packets
Figure 2‐03. Internal Data Flow Diagram
1.
2.
1.
2.
© 2007 Digi International, Inc.
If the module is receiving a continuous stream of RF data, any serial data that arrives on
the DIN pin is placed in the serial receive buffer. The data in the serial receive buffer will be
transmitted over-the-air when the module is no longer receiving RF data in the network.
When data is ready to be transmitted, the module may need to discover a Network Address
and/or a Route in order to reach the destination node. Discovery overhead may delay
packet transmission.
Refer to the ZigBee Networks --> Mesh Routing sections for more information.
could receive data faster than it can send the data to the host.
because of being held off by hardware flow control.
If the RF data rate is set higher than the interface data rate of the module, the module
If the host does not allow the module to transmit data out from the serial transmit buffer
Chapter 2 ‐ RF Module Operation
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