TR-916-SC-P Linx Technologies Inc, TR-916-SC-P Datasheet - Page 9

• Manufacturer Part Number: TR-916-SC-P
• Description: TRANSCEIVER RF 916MHZ 1/2-DUPLEX
• Manufacturer: Linx Technologies Inc
• Series: SCr

Specifications of TR-916-SC-P

• Frequency: 916MHz
• Data Rate - Maximum: 33.6kbps
• Modulation Or Protocol: FM, FSK
• Applications: ISM, Garage Door Opener, Remote Controls, 2-way RKE
• Power - Output: -10dBm
• Sensitivity: -94dBm
• Voltage - Supply: 2.7 V ~ 13 V
• Current - Receiving: 15mA
• Current - Transmitting: 19mA
• Data Interface: PCB, Through Hole
• Antenna Connector: RP-SMA
• Operating Temperature: 0°C ~ 70°C
• Package / Case: Module
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Memory Size: -
• Other names: TR-900-SC; TR-900-SC; TR-916-SC; TR-916-SC

It is important to note that the TR-XXX-SC does not encode or packetize the data
in any manner. This transparency eliminates the issues of variable latency
common to traditional radio modems and gives the designer tremendous
flexibility in the structure of protocol. A drawback to this approach is that the
performance and reliability of the link is in part determined by the quality of
external software and hardware.
The SC series is a half-duplex transceiver, meaning it can only act as a
transmitter or a receiver at any given time, but never both. Designing a system
with a half-duplex transceiver can be a bit challenging because of the timing
requirements when shifting between transmit and receive modes. A typical
systems operation would be similar to the following:
1)
The transceiver is placed in transmit mode by bringing TXEN high and RXEN
low. The PDN pin must be open or pulled to VCC. Once the transceiver is placed
in transmit mode, the synthesizer will begin trying to lock.
2)
This step is necessary to allow the transmitter time to lock and stabilize. Several
options are available during this time. The designer might choose to set a fixed
delay equal to the worst-case stabilization time before sending data. Another
method would be to send data immediately, knowing that it would not be valid
until the transmitter had stabilized. Depending on packet size, the latter method
may achieve faster turnaround times but would require more care from a protocol
standpoint.
3)
Structuring the data to be sent into small packets is highly recommended. That
way, errors can be managed easily without affecting large amounts of data.
Packets should be transmitted so that there is no space between bytes. When
using a UART the following packet format is generally followed:
[ uart sync byte ] [ start byte ] [ data packet ]
The UART Sync Byte is used to ensure that the start-bit for the start byte will be
accurately detected. It is a single byte with a value of 255 (0FF hex).
A Start Byte often follows the Sync Byte to intelligently qualify the Data Packet
which will follow. Detection of the Start Byte would be performed by the computer
or microcontroller connected to the transceiver.
4)
The transceiver is placed in receive mode by bringing RXEN high and TXEN low.
The PDN pin must be open or pulled to VCC. Once the transceiver is placed in
receive mode, the PLL will begin trying to lock.
5)
This step is necessary to allow the receiver time to stabilize. When the PLL is
locked and the data slicer is stable, the transceiver is ready to receive valid data.
During the settling time the receiver output may produce scraps of data; however,
the data can only be considered reliable once the settling time has passed.
Switch to transmit mode
Wait for transmitter to stabilize
Transmit a packet
Switch to receive mode
Wait for receiver to stabilize