LICAL-TRC-MT001 Linx Technologies, Inc., LICAL-TRC-MT001 Datasheet - Page 7

• Manufacturer Part Number: LICAL-TRC-MT001
• Description: Mt Series Transcoder Data Guide
• Manufacturer: Linx Technologies, Inc.

LATCH MODE
TARGETED DEVICE ADDRESSING
CUSTOM DATA TRANSMISSION
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The transcoder has two output options based on the state of the LATCH line. If
the line is low, then all of the status line outputs will be momentary, meaning that
they will only be high for as long as a valid signal is received. Once the signal
stops and the transcoder times out, the lines are pulled low.
If the LATCH line is high, then the transcoder will use a Latch Mask on the
outputs. By default, all of the status line outputs are set to latch, so the
transcoder will pull a data line high upon reception of a valid signal and hold it
high until the signal is received a second time, at which point the transcoder will
pull it low. The transcoder must see a break and time out of Receive Mode
between valid transmissions before it will toggle the outputs.
The Latch Mask can be changed through the SIE so that individual status lines
can be set as latched or momentary. The Serial Mode section has more
information on the SIE.
One of the powerful features of the MT is Targeted Device Addressing. This is
the ability to target the specific device that is to acknowledge the transmission.
This is accomplished by entering the address of the target device through the
SIE. For example, if a master controller needs Device 10 to activate, a
microcontroller or PC can be used to program the address of Device 10 into the
transcoder in the master controller. The transcoder will then broadcast that
address with the commands, and only Device 10 will respond. This enables
many types of master-slave, peer-to-peer, and even basic networking systems
to be quickly realized. The simple command set and open architecture allow
such systems to be implemented in many ways. Application Note AN-00157
goes into this feature in more detail.
Targeted Device Addressing only needs to be enabled on the transmitting side.
The receiving side identifies the packet as a targeted packet and responds
appropriately. This option is disabled by default.
The MT Series offers the option of sending one byte of custom data with the
command packet. The custom byte is entered into the transcoder through the
SIE using the Read and Write Custom Data Value commands. This option is
enabled or disabled using the Enable and Disable Custom Data commands. The
custom data byte is output on the receiving end with the TX ID and Status bytes.
Custom Data Transmission only needs to be enabled on the transmitting side.
The receiving side identifies the packet as containing custom data and outputs
the byte. This option is disabled by default and the receiving transcoder outputs
a value of 0xFF for the custom byte.
This feature is useful for sending an 8-bit A/D value from a sensor, custom
command codes, or an additional user-defined ID for additional proprietary
system authentication. There are no restrictions on the 8-bit value, though 0xFF
is not recommended for use since that is the default value with no data.
The Custom Data is output with the Status and TX ID bytes, as described in the
Serial Output section.
MODE ENTRY TIMINGS
Figure 5: MT Series Mode Entry Timings
Figure 6: MT Series Transmit Timings
Figure 7: MT Series Receive Timings
TR_DATA
MODE_IND
SER_IO
TR_SEL
D0 - D7
The transcoder may enter the desired mode within minimum timings shown in
the figure below. However, if the transcoder is in another mode at the time the
CRT/LRN line goes high, then it could take longer for the transcoder to recognize
the trigger. For example, Receive Mode at 9,600bps can take 32mS to exit. For
this reason, it is recommended to increase the time to ensure that the transcoder
will enter the correct mode. Typical times are shown in the figure, but may be
adjusted according to the application.
D0 - D7
TR_PDN
TR_SEL
TR_DATA
CONFIRM
Time t does not matter as
long as ENC_SEL goes
high before CRT/LRN.
Data In
Output
placement in memory)
80µS
CRT/LRN
ENC_SEL
(depends on user
520µS to 2.3mS
Input
Create Mode
20µS
t
120µS min
(35mS typ)
765µS
5µS
15µS
features and
Depends on
(depends on
Latch Mask)
baud rate
50 to 75µS
Data Out
Output
15µS
10µS
1.39 to 6.25mS
(depends mode
and baud rate)
on receiver
CRT/LRN
ENC_SEL
Depends
Input
Learn Mode
640µS
3.4 to 8.0mS
(depends on
Confirm
baud rate)
120µS min
(35mS typ)
3.4 to 8.0mS
(depends on
baud rate)
Confirm
560µS
10µS
32µS
Output
Input
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