AC4790-200A-485 Laird Technologies, AC4790-200A-485 Datasheet - Page 56

• Manufacturer Part Number: AC4790-200A-485
• Description: TXRX 900MHZ 3.3-5.5V FHSS 200MW
• Manufacturer: Laird Technologies
• Series: AeroCommr

Specifications of AC4790-200A-485

• 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: On-Board, Chip
• Operating Temperature: -40°C ~ 85°C
• Package / Case: Module
• Wireless Frequency: 900 MHz
• Interface Type: 20-pin mini connector
• Board Size: 49 mm x 42 mm x 5 mm
• Modulation: FHSS, FSK
• Security: 1 byte System ID, DES
• Operating Voltage: 3.3 V to 5.5 V
• Output Power: 200 mW
• Antenna: Integral and External Dipole
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Memory Size: -
• Current - Receiving: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

5 2
A P P E N D I X I I I - A P I
L O O P B A C K R E P E A T E R
The simplest repeater to implement is a loopback repeater. A loopback repeater can be created by connecting the
transceiver’s RXD and TXD lines together. When the radio receives data, it will retransmit the data to all available
transceivers on the network. It is important not to have two loopback repeaters in range of each other as they will
continuously transmit data back and forth.
If radios B & C in the above picture are not within range of radio A, they will not be able to receive or respond to
communications from radio A. A loopback repeater can be added between the three such that it is in range of both
2
3
4
Radio B receives the packet “FIND D”, and stores it in the buffer until the current session with Radio
A has ended. Once the current session ends, Radio B forwards the packet from its buffer to Radio C.
Radio C receives the packet “FIND D”, and stores it in the buffer until the current session with Radio
B has ended. Once the current session ends, Radio C forwards the packet from its buffer to Radio
D.
Radio D receives the packet “FIND D” and sends the appropriate response back down the line to
Radio A.
MAC 12 34 56
A
Loopback Repeater
MAC 12 34 A1
MAC 12 34 A2
B
MAC 12 34 A3
C