JPS58195350A - Data transmission system - Google Patents

Abstract

PURPOSE:To make the transmission time constant and to reduce malfunction, by making each bit of a long and a short code of a data transmission system using codes of the RZ pulse width modulation system equal with each other and transmitting consecutive short pulses by making two pulses a pair. CONSTITUTION:A long pulse is conventional in shape, but a short pulse is concaved as shown in Fig. B, and two short pulses are used as a pair. That is, in reading the pulse by using the leading edge as a start point TO, the long pulse is processed the same as in the conventional system but short pulses are sampled twice as signals S2, S3, and it is discriminated zero when the result is all L level. That is, the reading of the same timing 1, 0 is possible from the leading edge, and it is discriminated from the case when one short pulse noise is given by one. As signals S4-S7, the sampling is executed at each point of time of 1.5T and 2.5T from the leading edge as the start point TO, and it is possible to discriminate H, H as 1 and L, H as 0. The pulse used for such the case, is generated optionally by using a pulse generating circuit incorporating a timer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data transmission system, and particularly to a data transmission system using a signal waveform of an RZ (!J turn-to-zero) pulse width modulation system.

2. Description of the Related Art As a general data transmission method for serially transmitting digital data, a method using pulse width modulated RZ format long pulses and short pulses is known.

Figure 1.3 is a waveform diagram showing an example of such a signal waveform. 142
1-2- formed by signals as shown in Figure #'il1
FIG.

1. In other words, what is shown in Figure 1 is the signal high (t
l) Ratio between level and low (L) level, 2:
l (D) is used as ``1'' (see figure (a)), and the ratio l:1 is used as 0'' (see figure (b) #). Therefore, these When the signals are combined to form 4-pit data as shown in Figure 2 (a), ←), @"1001" and 11101"
The disadvantage is that the data word length differs between the two, and the transmission time per word length differs depending on the data content. On the other hand, as shown in Figures #&3, when the ratio of H level to L level is 3:l, it is a long pulse (see Figure 1), and when it is 1:3, it is a short pulse (see Figure 2). One possible method is to use it as The 1-bit length of these long and short codes is 4T (T; time width), and the word length is constant regardless of the data content. ) as the starting point (sampling period is 2T, for example), even if a noise like noise occurs, it should be bound to 10" (to avoid the risk of It's south.

This invention was made under such circumstances, and the purpose is to provide a one-night transmission system that requires only one data payment plus WJ, and has a low data error rate.

In the T-Yu transmission method, which transmits data using the code of the ltZ Hals 1-Shokutai method, it is long.

By making the lengths of each hint of the short code equal to each other, and by transmitting a set of two consecutive pulses, the data transmission time is kept constant and the number of -movements is reduced. .

Hereinafter, the implementation of this invention will be explained with reference to the drawings.
1. Detailed explanation of this invention is shown in Figure 4. In the Cth explanatory diagram, (U) is the signal waveform to be transmitted and part 1.
The 1° reading position indicates the sampling timing, and the 5l-
8.ttt sampling (indicates No. 1).

As is clear from the same figure, the long pulse (see #(a) in the same figure) is similar to that shown in FIG. 1- or FIG. 3. , On the other hand, the short pulse is different from the conventional one, as shown in the same figure (b).
It has a concave shape, and two short pulses are used as a pair. In other words, does it cause a sign to start? gi,
'o', the long pulse is the same as before, but the spider pulse is t and the signal s2. S, Unonyo (sampling is performed twice, and when both results are T, (low) level, 0”
It is determined that By doing this, you can get the same timing from the beginning of each signal.
It is possible to read l'' and 'O', and therefore it is possible to judge whether kJ is easy to enter by short pulse noise l) by μ°.
I can do something. However, there are 2 short pulse noises!
Needless to say, if you join, you will be disqualified from FiM, but
This J2□ case is extremely rare, so it is rarely used in practice.
is not a problem. In addition, the sampling time point is indicated by the rising edge (
'Do sampling and if it is 1H", 'H' then 1"'
It is also possible to determine that it is 0 if it is “l”, “l,” or “H”. In addition, these (Rus has a built-in timer) pulse generation rate of 1mM fathom used in this invention (.
It can be generated arbitrarily.

As described above, according to the present invention, )LZno(cis1-
Since the long and short code lengths of the adverb system are made stronger, the frame length becomes constant, and the #i-axis characteristic of the data is significantly improved because it is possible to distinguish between loose noises. It brings about

[Brief explanation of the drawing]

FIGS. 1 and 3 are waveform diagrams showing general signal waveforms using the RZ Nockles width modulation method, and FIG. 2 is an explanatory diagram for explaining data formed by the code format shown in FIG. 1.
FIG. 4 is an explanatory diagram showing the relationship between the signal waveform and the gun-picking timing according to the RZ pulse variable sea bream method used in the present invention. Code 1 light lm, Lj... (111/Bell, T...
・〕Russu period or Manshilling period, TO・・・・
...Start-up?) Point Agent Patent Attorney Kiyoshi Matsuzaki

Claims (1)

[Claims] In the RZ (IJ turn-to-zero) pulse width f11 method, a data transmission method that transmits data by combining long and short codes, the short codes are made into a set of two consecutive short codes,
Furthermore, the data transmission method is characterized in that each bit length of the short code is transmitted by making each bit length of the short code equal to each other, so that the word length of the transmitted data is equalized, and noise can be easily detected.