If the LEARN line is held high at the same time as the SEND_COPY line, the
decoder will enter Send Copy Mode. Once in this mode, the state of
the LEARN line is not checked again, so it can be held high or pulled to
ground, whichever is more convenient for the application.
If the LEARN line is held high at the same time as the CREATE_KEY line,
the decoder will enter Create Key Mode.
Decoder TX ID
Upon receipt of the first valid packet, the decoder will output a binary
number on the KEY_OUT line that corresponds to one of the learned
transmitters. It will output the number only once, as soon as the first
packet is accepted. An encoder’s key, a 40-bit counter, and permissions
are stored in one of 15 memory locations within the decoder. The decoder
is able to output an 8-bit binary number that corresponds to the memory
location of the encoder’s information. The first encoder that is learned will
be assigned 1, the second will be assigned 2 and so on. Once assigned, it
is an easy task for a software program to read that number and associate it
with a particular encoder. This makes applications such as logging access
attempts simple.
The ID will be asynchronously output as an eight-bit binary number at the
baud rate selected by the SEL_BAUD line. For example, if the SEL_BAUD
line is grounded and the first encoder that the decoder learned sends a
signal, then once the first packet is received, the decoder will output ‘0000
0001’ (binary 1) at 2,400bps on the KEY_OUT line.
Application Note AN-00156 shows an example program that will read this
number and display it on an LCD screen. The code is written in C and is
well documented so that it can be easily modified for a specific application.
The code and include files can be downloaded as a .zip file from the Linx
website.
Send Copy Mode
The HS Series decoder has the ability to send a copy of all of the learned
encoders to another decoder. This makes it possible to use the same
transmitter, encoder, and Control Permissions in multiple locations. Send
Copy Mode is entered when the SEND_COPY line and the LEARN line are
taken high at the same time. Once in this mode, the decoder will output all
of its User Data on the KEY_OUT line for asynchronous transfer to another
HS Series decoder. The decoder that receives the User Data becomes a
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