Linx Technologies LICAL-TRC-MT - Manual (Page 10)

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Custom Data Transmission
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
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 enters the correct mode.
Typical times are shown in Figure 8, Figure 9 and Figure 10, but may be
adjusted according to the application.
CRT/LRN
Learn Mode
ENC_SEL
120µs min
(35ms typ)
CRT/LRN
Create Mode
ENC_SEL
120µs min
(35ms typ) Time t does not matter as
long as ENC_SEL goes
high before CRT/LRN.
t
CRT/LRN
Serial Mode
SER_IO
120uS min
(50mS typ)
120uS
Figure 8: MT Series Mode Entry Timings
D0 - D7
TR_PDN
TR_SEL
TR_DATA
80µs 20µs 765µs
CONFIRM
10µs 32µs 560µs
Data Out Confirm
Depends on
features and
baud rate
Depends
on receiver
3.4 to 8.0ms
(depends on
baud rate)
Output Input Output
Figure 9: MT Series Transmit Timings
D0 - D7
TR_SEL
TR_DATA
15µs
520µs to 2.3ms
(depends on user
placement in memory)
MODE_IND
SER_IO
Output Input
5µs
50 to 75µs
(depends on
Latch Mask)
15µs
1.39 to 6.25ms
(depends mode
and baud rate)
640µs
3.4 to 8.0ms
(depends on
baud rate)
10µs
Data In Confirm Input
Figure 10: MT Series Receive Timings