JPH0479199B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data transmitting device using a frequency-based polling/selecting method.

[Conventional technology]

As shown in FIG. 5, when collecting data by independently driving a plurality of terminals 1 in remote locations, a common control line 2 is provided, and each terminal 1 is connected to a different specific control line. Generally, when a frequency signal is sent from the control unit 3, the terminal 1 corresponding to that specific frequency operates.

Conventionally, frequency identification in each of these terminals 1 has been performed using a mechanical filter or the like.

[Problem that the invention seeks to solve]

In the conventional frequency identification circuit using a mechanical filter or the like as described above, parts have to be changed every time the response frequency changes, making it impossible to reduce costs. Furthermore, since common parts cannot be used, there is a problem in that it is necessary to have spare parts for each type of frequency in case of failure.

The present invention was made to solve this problem, and an object of the present invention is to provide a data transmitting device that uses common parts.

[Means for solving problems]

The data transmitting device according to the present invention includes a frequency setting section for setting its own assigned frequency using a polling method; detecting a changing point of a pulse of an input signal using a sampling pulse; and detecting a changing point of a pulse of an input signal using a sampling pulse; Pulse cue means that counts a predetermined number (N times) determined by its own frequency and sets the center point of the pulse of the input signal;
The pulses of the input signal are sampled at a period corresponding to the frequency set by the frequency setting section from the center point of the pulse of the input signal detected by the pulse cueing means, and the acquired level is at the center point. a sampling level determination means for outputting an error when the frequency is different from the level; a timer means for measuring a measurement time corresponding to the frequency set by the frequency setting section; The error limit value corresponding to the set frequency is compared with the error count value output from the sampling level determination means, and if the error count value is smaller than the error limit value, the a control unit that includes arithmetic processing means that determines a set frequency and outputs a trigger; an input signal detection unit that activates the control unit when an input signal is detected; data that imports data from the outside. The device includes an interface section; a switching circuit that turns on power to the data interface section in response to a trigger from the control section; and a transmitting circuit that transmits the output from the data interface section.

[Effect]

In this invention, when the input signal is detected, the control section is activated by the input signal detection section, the pulse cue means in the control section detects the central part of the peak or valley of the pulse of the input signal, and the sampling level determination means starts sampling from this point, and outputs an error if the captured level differs from the reference value. Furthermore, when the timer means times out, the arithmetic processing means compares the error limit value and the error count value, and determines that the frequencies match if the error count value is smaller than the error limit value. Outputs the trigger shown. Then, when this trigger is supplied to the switching circuit, power is turned on to the data interface section, data is taken in, and this output is transmitted by the transmitting circuit.

〔Example〕

FIG. 1 is a diagram showing the configuration of an embodiment of a data transmitting device of the present invention. In this figure, 10 is a filter circuit, 11 is a limiter amplifier that generates a pulse waveform, 12 is an input signal detection section, 13 is a frequency setting section using, for example, a dip switch, 1
4 is a control unit using a CPU, which includes pulse cue means,
It includes a sampling level determination means, a timer means, and an arithmetic processing means. 15 is a constant voltage circuit;
16 is an interface, 17 is a switching circuit, 18 is a data interface section, and 19 is a transmitting circuit.

Next, the operation will be explained.

The filter circuit 10 has a control unit 14 activated when an input signal is detected by the input signal detection unit 12 to determine whether the frequency set by the frequency setting unit 13 and the frequency of the input signal are the same. and only when it is determined that they are the same, a trigger is sent out to activate the switching circuit 17. This enables the data interface unit 18 to operate. The data detected by the data interface unit 18 is sent to the outside via the transmitting circuit 19 and the interface 16.

Here, frequency discrimination (filter operation) by the control unit 14 will be explained.

First, upon receiving the output of the input signal detection section 12, the pulse cue means in the control section 14 is activated, and as shown in FIG. Detect approximately the center of a mountain (or valley). Specifically, as shown in the flowchart of FIG. 3a, after detecting the rising edge of the pulse, which is the changing point of the pulse, by performing M level determinations, the frequency is set in advance by the frequency setting unit 13 from that rising point. The number of times (N
(3) Level determination is performed, and when the input signal is at the assigned own frequency, the pulse cue means detects the center point that is approximately the center of the pulse peak. At this point, steps (2) and subsequent steps of the program for realizing the sampling level determining means, timer means, and arithmetic processing means shown in the flowchart of FIG. 3B are executed.

Here, the sampling level determination means is
A frequency equal to the frequency set from approximately the center of the peak (or valley) of the pulse (or the period is an integral multiple)
This is a means for sampling an input signal and determining whether the input level is "H" or "L".

In this embodiment, as described above, sampling is performed using the center of the pulse peak ("H") as the starting point by the pulse cue means, so that at least a signal of the frequency set by the frequency setting section 13 is input. In this case, the level taken in should always be the reference value "H" regardless of the passage of time, as shown in FIG. 4a, for example.

In addition, as shown in Figure 4b, the arithmetic processing means means that when the input level is not always "H", each time this occurs, it is counted as an error, and the timer means is used to process the error once. When the error count value is smaller than a preset error limit value at the end of the measurement time, the frequency is determined to be the same as the set frequency, and a trigger is output.

Next, FIG.
The flowchart shown in will be explained.

After the above-mentioned pulse search is performed in step (1), sampling is started (step (2)). And if the level is “H”,
1 by a subroutine as shown in Figure 3a.
At the same time, the timer count value is incremented (step (5)).
(6)).

On the other hand, if it is determined in step (2) that the level is not "H", the process proceeds to step (4), where the error count value is incremented, and then the process proceeds to step (5).

Then, steps (2) to (6) are repeated until a timeout is determined in step (7), and if a timeout is determined in step (7), step (8) is executed.
Then, it is determined whether the count value of the number of errors is greater than the error limit value. Then, if it is not determined that the value is large, a trigger is output. In other words, it operates as a filter only for specific frequencies.

Therefore, when the data transmission device of the present invention shown in FIG. 1 is applied to the system shown in FIG. This makes it possible to reduce costs, and also makes maintenance easier. In addition, since processing can be performed in software using a CPU, it is possible to achieve miniaturization, short determination times can be achieved even with a low frequency clock, and power consumption can be kept low.

〔Effect of the invention〕

A frequency setting section for setting the assigned own frequency using a polling method; detects a changing point of the input signal pulse using a sampling pulse, and sends a sampling pulse from that changing point to a predetermined number determined by the own frequency; (N times) and sets the center point of the pulse of the input signal as the center point of the pulse of the input signal; The pulses of the input signal are sampled at the corresponding period, and if the captured level is different from the level at the center point,
sampling level determination means for outputting an error; timer means for timing a measurement time corresponding to the frequency set by the frequency setting section; and timer means for measuring a measurement time corresponding to the frequency set by the frequency setting section for each measurement time. The error limit value is compared with the error count value output from the sampling level determining means, and if the error count value is smaller than the error limit value, the frequency is determined to be the set frequency. and a control section including an arithmetic processing means for outputting a trigger; an input signal detection section for activating the control section when an input signal is detected; a data interface section for taking in data from the outside; Since it includes a switching circuit that turns on power to the data interface section in response to a trigger from the control section; and a transmitting circuit that transmits the output from the data interface section, frequency discrimination is actively performed. , the data transmitting devices that operate in response to input signals of different frequencies can all be constructed from the same parts, which has the effect of reducing costs and facilitating maintenance.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of the data transmitting device of the present invention, FIG. 2 is a diagram for explaining the cue operation, and FIGS. 3 a and b are flowcharts for explaining the operation. , FIGS. 4a and 4b are diagrams for explaining an example of sampling, and FIG. 5 is a schematic diagram for explaining a data collection system. In the figure, 1 is a terminal, 2 is a control line, 3 is a control unit, 1
0 is a filter circuit, 11 is a limiter amplifier, 12
13 is an input signal detection section, 13 is a frequency setting section, 14 is a control section, 15 is a constant voltage circuit, 16 is an interface section, 17 is a switching circuit, 18 is a data interface section, and 19 is a transmission circuit.

Claims (1)

[Claims] 1. A frequency setting unit 13 connected to the control unit 3 and configured to set its own frequency allocated by the polling scheme in a data transmitting device using a polling scheme driven by a frequency sent from the control unit; Pulse cueing that detects the changing point of the input signal pulse using a sampling pulse, counts the sampling pulse a predetermined number (N times) determined by its own frequency from the changing point, and sets the center point of the input signal pulse. sampling the pulses of the input signal at a period corresponding to the frequency set by the frequency setting section from the center point of the pulse of the input signal detected by the pulse cueing means, and the captured level is set at the center point of the input signal. a sampling level determining means for outputting an error when the level differs from the level of the point; a timer means for measuring a measurement time corresponding to the frequency set in the frequency setting section; The error limit value corresponding to the frequency set by the section is compared with the error count value output from the sampling level determination means, and if the error count value is smaller than the error limit value, , a control unit 14 equipped with an arithmetic processing means that discriminates from the set frequency and outputs a trigger; an input signal detection unit 12 that activates the control unit when an input signal is detected; Data interface section 18 that imports data
A switching circuit 17 for turning on power to the data interface section in response to a trigger from the control section; and a transmitting circuit 19 for transmitting an output from the data interface section. Transmitting device.