JPS5852275B2 - automatic scanning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic scanning device having a function of sequentially outputting a plurality of parallel electrical signals from one output terminal.

First, a conventional automatic scanning device will be described by showing a temperature identification device to which this automatic scanning device is applied.

The temperature identification device is used, for example, in a spinning factory, and is used to determine and display whether the temperature at each location within the factory is appropriate or inappropriate for spinning.

By applying an automatic scanning device to this temperature identification device, it is possible to output an electric signal corresponding to the temperature of each location from one output terminal, which is extremely preferable from the viewpoints of operability and economy.

FIG. 1 shows a temperature identification device to which a conventional automatic scanning device is applied.

In FIG. 1, a temperature sensitive resistance element 1 is connected to each of n input terminals 01, and a constant current source 31 is connected to each of them via a contact 21.

This temperature-sensitive resistance element 1 is placed at each temperature measurement location.

The n contacts 21 constitute a contact group 2, and the output of the shift register 22 is sent to this contact group.

That is, the n contacts 21 are configured to turn on and off in accordance with the parallel outputs of the shift register 22, respectively.

Then, as the contents of the shift register 22 are shifted in accordance with the shift pulses of the pulse oscillator 23, only one contact 21 is turned ON sequentially.

Therefore, current flows sequentially from the constant current source 31 to the n temperature-sensitive resistance elements 1 in accordance with the shift of the shift register 22.
The voltage corresponding to the temperature at the installation location of each temperature-sensitive resistance element 1 is
This occurs at the connection point between the contact 21 and the constant current source 31.

This voltage is converted into digital data by the AD converter 32 and sent to the comparator 35.

A low level reference value SL and a high level reference value sH are sent to this comparator 35 from reference value setting circuits 33 and 34.

The reference values SL and SH set the lower and upper limits of the appropriate temperature.

The output V of the AD converter 32 is SL>■ or v>s
When the temperature is H, an inverted signal is input to the next stage flip-flop 36 and stored, and the lamp 37 is driven to indicate that the temperature is not appropriate.

On the other hand, when SL≦■≦SH, the flip-flop 36 is not inverted and the lamp 37 is not driven.

Therefore, depending on the shift of the shift register 22, the suitability or unsuitability of the temperature at each installation location of the temperature-sensitive resistance element 1 is sequentially determined and displayed on the lamp 37.

By the way, there is no problem when connecting the temperature sensitive resistance element 1 to all n input terminals 01 as described above, but when using one type of automatic scanning device (with a fixed number of input terminals), various inputs can be performed. When used for purposes with a limited number of terminals, various problems arise.

For example, when the number of temperature detection points is m (n>m≧1), conventionally the temperature sensitive resistance element 1 is not connected [n-m
An equivalent resistance is connected to one input terminal 01 (hereinafter referred to as an empty channel), and the output ■ of the comparator 32 corresponding to the empty channel is set to a predetermined value of sL≦■≦sH, and an inverted input is sent to the flip-flop 36. I try not to.

Therefore, each time the reference levels sI, . . . , sH are set, the corresponding resistors must be reconnected.

Further, when the input signal for scanning is a current input or a voltage input depending on the necessity, adjustment is even more difficult, making it practically impossible for general users to use.

For this reason, it would be possible to change the model of the automatic scanning device depending on the number of input terminals, and select the model according to the application, but this would increase costs as each model would have to be manufactured and stocked. becomes.

In view of the above, the present invention determines whether each of a plurality of input terminals is used or not, and sequentially outputs only the signals input to the input terminals in use from the output terminal,
The object of the present invention is to provide an automatic scanning device that solves problems in terms of price and use.

Embodiments of the present invention will be described below with reference to FIGS. 2 and 3.

Note that in FIG. 2, parts corresponding to those in FIG. 1 are given corresponding numbers, and explanations thereof will be omitted.

FIG. 2 shows a first embodiment.

In other words, the feature of this embodiment is that it is equipped with a comparator 39 that grounds an empty channel and generates a detection output when an extremely small digital amount corresponding to the ground is output from the decoder. The point is that the detection signal is sent as a prohibition input to the comparator 35 so that no output is generated during the period when this detection output is generated.

Note that the comparator 39 generates a detection output when the input signal is less than a reference value, and the reference value setting circuit 38 sets a value that is slightly larger than an extremely small digital amount corresponding to the ground.

Therefore, in this first embodiment, the shift register 22
In response to the shift of , the temperature of the set value of the temperature sensitive resistor element 1 is sequentially checked, and when an empty channel is checked, a prohibition input is sent to the comparator 35 to prevent the lamp 37 from being erroneously driven.

In particular, it should be noted that even when the reference values SL and SH are changed, the device can be used without any readjustment.

FIG. 3 shows a second embodiment.

Note that in FIG. 3, parts corresponding to those in FIG. 1 or 2 are given corresponding numbers, and explanations thereof will be omitted.

That is, in FIG. 3, the detection output of the comparator 39 is input to the pulse generator 40 to generate one pulse, which is sent to the clock input terminal of the shift pulse generator 32 via the OR circuit 41.

Therefore, the shift pulse output from the pulse oscillator 23 is input to the output terminal of the shift register 32 via the OR circuit 41, and as the contents of the shift register 22 are shifted, temperature verification is performed sequentially.

Then, when the empty channel is detected, comparator 3
A detection output is generated from 9, and in response to this output, one pulse is sent from the pulse generator 40 to the clock input terminal of the shift register 22, and the shift register 22 is immediately shifted by l clocks, and the next verification is performed.

Of course, in this case as well, the comparator 35 is prohibited.

In particular, it should be noted that this embodiment can speed up the identification by shortening the unnecessary time required to identify empty channels.

Note that, as shown by the dotted line in FIG. 2, the output of the pulse generator is input to the reset terminal of the shift register 22.

Then, m temperature-sensitive resistance elements 1 are used, and the temperature-sensitive resistance elements 1 are connected to the first to m-th input terminals 01,
Speed-up can be achieved by grounding the remaining [nm] input terminals 01 as empty channels.

In other words, by doing this, only temperature identification is performed sequentially.

After all the temperature checks from the first to the mth temperature checks are completed, the reset signal is immediately sent to the shift register when the (m+1)th empty channel is checked, and the temperature checks from the first to the mth ones are performed again. This is because unnecessary time of empty channels is almost eliminated.

Of course, as is clear from the above, the automatic scanning device configured as described above can achieve further speedup compared to the second embodiment, but it always uses all the 1st to mth
+1:] It is necessary to decide not to use all of the following.

Therefore, it would be best to select which channel to use depending on the purpose, taking into account the ease of use of any channel in the second embodiment.

As described above with respect to the embodiments, according to the present invention, it is determined whether each of a plurality of input terminals is used or not, and only the signals input to the input terminals in use are sequentially output from the output terminal. By doing this, it is possible to realize an automatic scanning device that solves problems in terms of cost or use, and also makes it possible to reduce loss time and shorten the scanning time, if necessary.

It goes without saying that the present invention is not limited to the above embodiments.

For example, if the unused terminal 01 is opened to ground, a large digital amount output from the AD converter 32 is connected to the comparator 39 and the reference value setting circuit 38.
It may be configured such that it is detected and a detection output is generated.

Further, analog amounts at a stage before the AD converter 32 may be compared.

In this way, the time required for the AD converter can be saved, which is advantageous in speeding up the process.

Further, when a double integral type AD converter is used, a configuration may be adopted in which the level of the integrated voltage is detected.

It goes without saying that the application is not limited to temperature identification devices.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional example, FIG. 2 is a block diagram showing a first embodiment and a modified example, and FIG. 3 is a block diagram showing a second embodiment. 01...Input terminal, 1...Temperature sensitive resistance element, 2...Contact group, 22...Shift register, 23...Pulse Oscillator, 31...
... Constant current source, 32 ... AD converter, 33
...Low level reference value setting circuit, 34...
...High-level reference value setting circuit, 35, 39...
・Comparator, 36...Flip-flop, 3
7...Lamp, 38...Reference value setting circuit corresponding to ground, 40...Pulse generator.

Claims (1)

[Claims] 1. A pulse oscillator, a shift register that steps every pulse input from the pulse oscillator and sequentially outputs a signal to the output terminal of each stage, a plurality of signal input terminals, and 1.
Each of the switches connected between the two common output terminals is controlled to open and close by the output of each stage of the shift register, and each one of the plurality of signal input terminals is sequentially switched to one common output terminal. In an automatic scanning device equipped with a switching circuit, the signal input terminal to be used as an empty channel among the plurality of signal input terminals is grounded or open, and the common output terminal and a reference potential source corresponding to the ground or open are connected. and an empty channel detection circuit which detects that the signal is from an empty channel by comparing their values and generates a detection output, and between the common output terminal and the load circuit. An automatic scanning device comprising: a prohibition circuit connected to the detection circuit for inhibiting a signal from the common output terminal from being output to a load circuit in response to a detection output of the detection circuit.