AC4490LR-200M Laird Technologies, AC4490LR-200M Datasheet - Page 25

• Manufacturer Part Number: AC4490LR-200M
• Description: TXRX 900MHZ 3.3-5.5V TTL 200MW
• Manufacturer: Laird Technologies
• Series: AeroCommr

Specifications of AC4490LR-200M

• Frequency: 902MHz ~ 928MHz
• Data Rate - Maximum: 115.2kbps
• Modulation Or Protocol: FHSS, FSK
• Applications: AMR, Fire & Security Alarms, Telemetry
• Power - Output: 5mW ~ 200mW
• Sensitivity: -110dBm
• Voltage - Supply: 3.3V, 5V
• Current - Transmitting: 68mA
• Data Interface: Connector, 2 x 10 Header
• Antenna Connector: MMCX
• Operating Temperature: -40°C ~ 85°C
• Package / Case: Module
• Output Power: 200 mW
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Memory Size: -
• Current - Receiving: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

AC4490 User’s Manual
Note: If Server A (with sync-to-channel enabled) cannot synchronize to Server B (on the sync channel), Server A will
not be able to communicate with its Clients and must wait until it synchronizes with Server B (at which point In_Range
will be asserted), before establishing communications. Server B will not be affected and can communicate with its
Clients.
Refer to the Sync-to-Channel Appendix for further details and sample configuration.
O N E B E A C O N M O D E / R A N G E R E F R E S H
One Beacon - The 4490 maintains synchronization by using the timing information in the Server’s beacon. This
beacon lasts approximately 1 ms and is transmitted by the Server at the beginning of every 20 ms hop. If One Beacon
mode is enabled, the 1 ms synchronization pulse is sent only once per complete hop cycle. For example, a Server
operating in Channel Set 1 (channels 0x10 - 0x2F) hops on 50 frequencies at 20 ms per frequency. By enabling One
Beacon mode, the server will only transmit a beacon every 1000ms (50 frequencies x 20ms). It can therefore take
anywhere from several seconds to minutes for the initial synchronization to occur. While One Beacon mode can
increase net throughput, it makes initial synchronization take longer and can make communications more difficult if
operating on the fringe.
Range Refresh - Range Refresh specifies the maximum amount of time a Client reports in range without having heard
a beacon from the Server. Each time the Client hears a beacon, it resets its Range Refresh timer. If the timer reaches
zero, the Client will go out of range, take In_Range pin High and enter aquisition mode attempting to find the Server
once again. The range refresh is equal to the hop period (20 ms) x Range refresh value.
Note: Range Refresh should not be set to 0x00.
A U T O C O N F I G P A R A M E T E R S
The AC4490 has several variables that vary by RF mode and architecture. By default, Auto Config is enabled and
bypasses the values stored in EEPROM and uses predetermined values for the given operating mode. Below is a list
of the variables controlled by Auto Config and their respective predetermined values. If Auto Config is disabled, these
values must be programmed in the transceiver EEPROM for the corresponding mode of operation.
EEPROM Address
RF Packet Size
Parameter
0x3C
0x3D
0x45
T a b l e 1 0 : O n e B e a c o n M o d e S e t t i n g s
T a b l e 1 1 : A u t o C o n f i g P a r a m e t e r s
EEPROM
Address
One Beacon Mode Enabled
0x36
0x5B
www.aerocomm.com
Set bit 7
0x18
0xFF
Default
0x66
0x46
Mode Disabled
One Beacon
0xA0
0x50
One Beacon Mode Disabled
Clear bit 7
0x28
0x48
S O F T W A R E I N T E R F A C E
Mode Enabled
One Beacon
0xA0
0x68
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