A09-HSM-7 Digi International/Maxstream, A09-HSM-7 Datasheet - Page 9

• Manufacturer Part Number: A09-HSM-7
• Description: ANT 900MHZ 7" STRAIGHT W/RPSMA
• Manufacturer: Digi International/Maxstream

Specifications of A09-HSM-7

• Antenna Type: Whip: 1/2 Wave
• Number Of Bands: 1
• Frequency: 915MHz (902MHz ~ 928MHz)
• Vswr: 2
• Gain: 2dBi
• Termination: RP-SMA
• Mounting Type: Connector
• Height (max): 7.0" (177.8mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2. RF Module Operation
2.1. Serial Communications
WARNING: When operating at 1 Watt power output, observe a minimum separation distance of 2' (0.6m) between
modules. Transmitting in close proximity of other modules can damage module front ends.
2.1.1. UART Data Flow
Serial Data
The XTend OEM RF Modules interface to a host device through a TTL-level asynchronous serial
port. Through its serial port, the module can communicate with any UART voltage compatible
device or through a level translator to any serial device (For example: RS-232/485/422 or USB
interface board).
Devices that have a UART interface can connect directly to the pins of the RF module as shown in
the figure below.
Figure 2‐01. System Data Flow Diagram in a UART‐interfaced environment
Data enters the module UART through the pin 5 as an asynchronous serial signal. The signal
should idle high when no data is being transmitted.
Each data byte consists of a start bit (low), 8 data bits (least significant bit first) and a stop bit
(high). The following figure illustrates the serial bit pattern of data passing through the module.
Figure 2‐02. UART data packet 0x1F (decimal number ʺ31ʺ) as transmitted through the RF module
The module UART performs tasks, such as timing and parity checking, that are needed for data
communications. Serial communications depend on the two UARTs to be configured with compati-
ble settings (baud rate, parity, start bits, stop bits, data bits).
© 2007 MaxStream, Inc.
(Low‐asserted signals distinguished with horizontal line over signal name.)
Example Data Format is 8‐N‐1 (bits ‐ parity ‐ # of stop bits)
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