Linx MDEV-868-NT, Руководство по данным, Страница: 12 / 23

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Power Level vs. Resistor Value
Power
Level
P
O
(dBm)
1%
Resistor
Value
Power
Level
P
O
(dBm)
1%
Resistor
Value
Power
Level
P
O
(dBm)
1%
Resistor
value
57 12.22 Open 38 3.49 154k 19 −5.47 44.2k
56 12.12 750k 37 3.11 143k 18 −5.78 41.2k
55 12.14 649k 36 2.77 133k 17 −6.12 37.4k
54 11.86 576k 35 2.12 127k 16 −6.72 34.8k
53 11.85 510k 34 1.65 118k 15 −7.09 32.4k
52 9.58 453k 33 1.16 111k 14 −7.52 29.4k
51 9.78 412k 32 0.81 105k 13 −7.91 26.7k
50 8.94 347k 31 0.38 97.6k 12 −8.36 24.3k
49 8.33 340k 30 −0.18 91k 11 −8.83 22k
48 8.02 316k 29 −0.66 86.6k 10 −9.39 19.6k
47 7.42 287k 28 −0.93 80.6k 9 −9.13 17.4k
46 6.99 267k 27 −1.46 76.8k 8 −9.68 15.4k
45 6.72 243k 26 −1.84 71.5k 7 −10.23 13.3k
44 6.33 226k 25 −2.39 66.5k 6 −10.86 11.3k
43 5.80 210k 24 −2.83 62k 5 −11.50 9.53k
42 5.38 200k 23 −3.27 57.6k 4 −12.23 7.5k
41 4.83 182k 22 −3.79 54.9k 3 −13.04 5.76k
40 4.33 174k 21 −4.30 51k 2 −13.98 4.02k
39 4.05 165k 20 −4.85 47k 1 −14.59 2.32k
0 −15.78 750
Channel Selection
The transceiver allows for setting the channel frequency with the
CHN_SEL0, CHN_SEL1 and CHN_SEL2 lines in a parallel manner. The
logic states of the three lines select from among eight channels. This allows
the channel to be set by DIP switches, microcontroller lines or hardwired.
The 868MHz channels are shown in Figure 25 and the 900MHz channels
are shown in Figure 26.
Baud Band Selection
Baud Band BAUD1 BAUD0
Baud Rate
(kbps)
IF Bandwidth
(kHz)
Receiver Sensitivity
(dBm)
1 0 0 1 to 19.2 100 −113
2 0 1 19.2 to 80 150 −110
3 1 0 80 to 160 200 −106
4 1 1 160 to 300 300 −102
Figure 23: NT Series Transceiver Power Level vs. Resistor Value
Figure 24: NT Series Transceiver Baud Band Selection
Baud Band Selection
There are two baud select lines (BAUD0 and BAUD1) that configure the
transceiver for the desired over-the-air data rate. The two baud select lines
choose among four baud bands, or ranges of data rate and IF bandwidth,
as shown in Figure 24.
Setting the baud band appropriately for the desired baud rate configures
the internal filters and circuitry for optimal performance at that rate. Data
can be sent in at a lower rate than specified for the band, but the sensitivity,
and therefore range, will not be as good as in a lower setting. Data can
also be sent in faster than specified by the band, but the internal filters will
cause distortion of the data stream and range will be significantly reduced.
868MHz Channel Selection
CHN_SEL2 CHN_SEL1 CHN_SEL0 CHANNEL FREQUENCY
0 0 0 0 863.15
0 0 1 10 864.15
0 1 0 20 865.15
0 1 1 30 866.15
1 0 0 52 868.35
1 0 1 58 868.95
1 1 0 64 869.55
1 1 1 67 869.85
Figure 25: NT Series Transceiver 868MHz Channel Selection