Linx Technologies LICAL-TRC-MT - Manual (Page 7)

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Transcoder Operation
When the transcoder powers on for the first time, it looks at the state of
the ENC_SEL line. If the line is high, then the transcoder enters Encoder
Mode and acts like an encoder only. It pulls the TR_SEL line high to set
the transceiver into transmit mode and makes all of its status lines inputs.
The transcoder does not have an address, so one must be created before
normal operation can start.
If the ENC_SEL line is low, then the transcoder enters Decoder Mode and
acts like a decoder only. It pulls the TR_SEL line low to set the transceiver
into receive mode and makes all of its status lines outputs. The transcoder
has not learned any addresses, so it will not respond to any transmissions.
Once a user is learned, the transcoder requires that the transmission have
a valid, learned address before it responds.
The process of creating an address also defines which status lines are
inputs and which are outputs. Once this is completed, if the ENC_SEL line
is high, then the MT Series acts as an encoder only using just the defined
inputs and the address that was created.
If the ENC_SEL line is low, the MT Series enters Transcoder Mode and
uses both the inputs and outputs as well as the address that was created.
In this mode, it can send commands as well as receive commands. It
must go through Learn Mode to learn another device's address before it
responds to transmissions.
MT Series Mode Entry Conditions
CRT/LRN ENC_SEL SER_IO Mode
1 0 0 Learn Mode
1 1 0 Create Mode
1 0 1 Serial Mode
Figure 7: MT Series Transcoder Mode Entry Conditions
Mode Entry
The MT Series transcoders have several modes for configuration and
operation. The different modes are entered based on the logic states of
three lines, as shown in Figure 7.
The activation of the CRT/LRN line begins the process. The transcoder
checks the ENC_SEL and SER_IO lines and enters the modes based on
their states. ENC_SEL and SER_IO should be set to the desired state
before activating CRT/LRN to ensure that the correct mode is entered.
Create Mode is used to give the transcoder a unique address and to set
Control Permissions.
Learn Mode is used to learn another transcoder's address.
Serial Mode is used to communicate with the transcoder using its Serial
Interface Engine (SIE).