SMARTALPHA-433 rfsolutions.ltd, SMARTALPHA-433 Datasheet - Page 4

• Manufacturer Part Number: SMARTALPHA-433
• Description: Smartalpha Rf Transceiver
• Manufacturer: rfsolutions.ltd

DSSMARTALPHA-2e.doc
2.
Operation Modes
Serial Data Format
CTS Timing
The Host Data Rate pins are read when the PD pin goes high. The SmartALPHA must be put into standby
mode by taking the PD pin low in order to change the selection.
The size of RF data packets are set during configuration. If fewer bytes are received by the SmartALPHA than
the preset size, then after 10ms from the last byte received from the host, the RF packet will be processed
(expanded to meet the preset packet size) and transmitted. The RF data packet size must be set the same for
transmitter and receiver, otherwise the received packets will be discarded.
In order to optimise data rate , in a point-to-point configuration where data is mostly being sent in one direction,
the packet size for one data direction can be set to the maximum size, however the reverse direction may be
set to a smaller packet size, to implement an acknowledge reply for example.
The RTS pin overrides the timeout value. If a short data packet is sent, RF transmission will start as soon as
the RTS pin is taken ‘high’ after the last byte is sent to the module.
The SmartALPHA contains an on-board data buffer equal to two data packets. Therefore if RTS is asserted
(then the host is unable to receive data) the SmartALPHA will store a max of two data packets, all further data
packets received will be discarded.
No RF packets will be received by the module when it is in power down standby mode.
Each SmartALPHA has its own preset address. This is set during configuration. Any data received is
examined and the address header embedded within the data packet is compared with the RF60 address. Only
data received with matching address will be processed and output to the host, all other data will be discarded.
All SmartALPHA modules are shipped with a default address of 7E7E7E7E.
The addressing protocol employed enables many different configurations such including:
one-to-one operation; for point to point data communication
broadcast operation; where a single master address many SmartALPHA modules concurrently. (using many
SmartALPHA modules set to the same address),
one-to-many; A network consisting a master and many slaves (the receivers all have the same address)
many-to-one; where the transmitters all send to a single receiver address.
Because each SmartALPHA can contain a unique address, multiple SmartALPHA networks can co-exist in
the same area.
The SmartALPHA serial format settings are:
Baud Rate:
Data Bits:
Parity: None
Stop Bits:
Flow Control: Hardware
With a standard buffer size of 30 bytes, CTS is asserted 41uS after the buffer is full. In cases where less
than 20 bytes are sent CTS is asserted after a timeout of 10mS.
Operation
Defined by DR1 and DR2 Pins
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©2009 REG No 277 4001, ENGLAND.
S
MART
ALPHA RF T
RANSCEIVER
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