ALPHA Encoder / Decoder IC’s
RF803-ALPHA
Serial Data Output
The RF803D-ALPHA has a serial data output. This outputs the serial number, button and
battery status of the transmitter encoder (RF803E-ALPHA). This data may be fed directly to a
microcontroller or RS232 type driver circuit which may then be fed directly to a PC serial port.
Serial data is output initially and again on every state change whilst data is being received from
the RF803E-ALPHA transmitter. i.e. this output is valid regardless of whether the RF803E-
ALPHA encoder has been learnt to the RF803D-ALPHA decoder or not. The serial data packet
contains a learn bit to show if an encoder input is learnt.
Serial Data Format
Serial Data is sent on every state change as a stream of 8 bytes at 19.2K baud. The serial data
format is: 8 data bits with 1 stop bit, no parity.
Serial data is output form the Decoder chip whenever a valid data packet from an RF80n or
other compatible RF Solutions transmitter is received regardless of learn
N
N
X
X
STAT $ 0D $0A
N
8 bytes of data transmitted
L
F Line feed (last character)
CR Carriage return
Battery Status / Learn Status
Encoder Input information
Encoder serial number
Output from Serial Data pin
Encoder Serial Number [NN]: made up of two 8-bit bytes where the most significant byte is
transmitted first.
This provides a total of 65,536 possible serial numbers.
Example: 12AB (hexadecimal) or 0001 0010 1010 1011 (binary)
DS803-ALPHA-1 Nov ‘09
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Tel 01273 898000 Fax 01273 480661
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