JPS6259810A - Transducer - Google Patents

Abstract

PURPOSE:To confirm an upper and a lower limit value during operation and to prevent them from being recognized as a current value by adding integrally a setting function for the specific range of an input signal and the function of a meter relay for obtaining an output when the signal exceeds the range. CONSTITUTION:An AC input from an input buffer 2 is A/D-converted 3 and supplied to a microcomputer (MC) 4. The MC 4 is provided with an XH and an XL flag which are set when a relay is driven while a current input value exceeds the upper or lower limit value, registers for storing the current value, and upper and lower limit values, etc. The MC 4 supplies the current value to a display device 6 and a latch circuit 7 at specific intervals of time on the basis of an external input and the circuit 7 supplies its output to a D/A converter 8. The converter 8 converts the digital signal into a DC output corresponding to the signal and the converted signal is sent out through terminals 9a and 9b. Further, the MC 4 supplies its output to an output buffer 10 when the input value exceeds the upper or lower limit value. The buffer 10 drives the relay XH or XL according to those inputs to drive light emitting diodes respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to transducers for converting physical quantities such as current, voltage, temperature, pressure, etc. into linearized outputs over a predetermined range.

[Summary of the invention]

The transducer according to the invention can be used for both current and voltage.

4. Convert input signals in a predetermined range of physical quantities such as temperature and pressure into signals at a predetermined level, and record the upper and lower limits of the input signal in advance. The meter relay function is set in the Q means and outputs an output when the input signal exceeds the upper and lower limits. During operation, the current value is displayed, and upper and lower limit values are displayed for a predetermined time as necessary.

[Background of the invention]

Conventional transducers, e.g. voltage transducers, convert the input voltage of a potential transformer (PT) e.g. It converts the current generated into a DC voltage within a certain range. Such various conventional transducers have only the function of converting an input physical quantity into a DC voltage within a predetermined range corresponding to the input physical quantity. Then, it is necessary to use a meter relay to display the input value, set the lower limit value and upper limit value of the input value, and obtain an output when the input value exceeds the range. However, the transducer and the meter relay are independent devices, and each needs to be wired separately, which makes the wiring complicated and requires a large installation space. Another problem is that the output voltage of the transducer and the upper and lower limits at which the meter relay operates do not necessarily match, making it difficult to use.

[Purpose of the invention]

The present invention has been made in view of the problems of conventional transducers, and provides a function for setting a predetermined range of input values in a transducer that converts an input signal into a DC voltage within a predetermined range, and a function for setting a predetermined range of input values and the range thereof. It is an object of the present invention to provide a transducer which is integrated with the function of a meter relay that obtains an output when the value exceeds the limit value, and whose upper and lower limit values can be checked during operation.

[Structure and effects of the invention]

The present invention is a transducer that converts an input signal into a signal of a predetermined level corresponding to the input signal, and includes an A/D converter that converts an analog input signal to a digital signal, and an upper limit value and a lower limit value of the input signal. Upper and lower limit value setting means, storage means for storing the current value and upper and lower limit values set by the upper and lower limit value setting means, and input signals A/D converted by the A/D converter and stored in the storage means. a comparison means for comparing the current value with the upper and lower limit values, an output means for outputting an output when the current value exceeds the upper and lower limit values as a result of comparison by the comparison means; A D/A converter that converts into a signal proportional to the level, a display that displays the upper and lower limits or the current value, a switching input means that switches the display on the display to the upper and lower limits or the current value, and a switching input means that converts the signal into a signal proportional to the level. The present invention is characterized by comprising a control means for switching to displaying the current value after a predetermined period of time after switching and displaying the upper and lower limit values.

According to the present invention having such characteristics, it is possible to obtain a linearized output within a predetermined range corresponding to the input signal, and when the input signal exceeds the upper and lower limit value range set by the upper and lower limit value setting means. This makes it possible to create a transducer with the function of a meter relay that obtains an output. Therefore, there is no difference between the display of the transducer and the output when the upper and lower limits are exceeded, making it possible to provide an easy-to-use transducer. In addition, during operation, the upper or lower limit value is displayed for a predetermined time by pressing the push button switch, and then automatically returns to the current value display, so that there is no possibility of mistakenly recognizing the upper and lower limit values as the current value.

Furthermore, compared to the case where a conventional transducer and meter relay are used, there are fewer wirings in the input section, and the configuration can be simplified. Therefore, compared to the case where two devices are used, it is possible to reduce the size and cost.

[Explanation of Examples]

(Configuration of Embodiment) FIG. 1 is a block diagram showing the electrical configuration of an embodiment of a transducer according to the present invention, and FIG. 2 is a front panel diagram thereof. This embodiment is a transducer that converts an AC input of 0 to 150V to a DC output of 0 to 5V. In these figures, an input amplifier 2 is connected between input terminals 1a and lb. The input buffer 2 receives an AC input at high impedance, divides the voltage, rectifies the divided voltage output, and supplies the rectified voltage to the A/D converter 3. The A/D converter 3 converts the analog signal applied at a predetermined timing into a digital signal and provides the output to the microcomputer 4.

The microcomputer 4 has a microprocessor and an input/output interface inside.

and a control element having a storage means having a control program and a register group shown in the figure. microcomputer 4
The internal registers include a P flag, an H flag, an L flag indicating the display status, an XH flag, an XL flag that is set when the current value exceeds the upper limit value and lower limit value and the relay is driven, and a push button switch PB5. A flag register is provided for the PB5 flag that is set when the button is pressed, and a pv value register that stores the current value, an H setting value register that stores the upper limit setting value, and an L setting value register that stores the lower limit setting value are provided. , and an internal timer is also provided. Also connected to the microcomputer 4 are a slide switch SI for switching between set mode and run mode, a push button switch FBI-PB4 for numerical setting that sequentially switches the display of each digit on the 11 display, and a push button switch PB5 for switching the display contents. , furthermore, the output of the model selection switch 5 is given. The model selection switch 5 provides data for setting this transducer to a predetermined input/output specification, and it is necessary to use the input cover sofa 2 that corresponds to the input/output specification. The microcomputer 4 provides the current value to the display 6 and latch circuit 7 at predetermined time intervals based on these externally applied inputs. The latch circuit 7 holds the output of the microcomputer 4 for a predetermined period of time, and supplies the output to the D/A converter 8.

The D/A converter 8 converts the digital signal into an output corresponding to the signal, for example, a DC output of O to 5■, and outputs it to terminals 9a, 9.
It is given to the outside via b.

The microcomputer 4 checks whether the input value exceeds the upper and lower limits. If the input value exceeds the upper and lower limits, an output is given to the output sofa 10. Output buffer 10 drives relay XH or relay XL in response to these inputs. Relays XH and XL have normally open contacts connected between terminals 11a, llb and 12a, 12b, respectively, and provide outputs to the outside from these terminals. Furthermore, when driving the relays XH and XL, the output buffer IO connects the light emitting diodes 13 at the top of each panel.
．． 14 (hereinafter referred to as LEDs) are respectively driven. Also, p indicates the current output of the display 6 from the microcomputer 4.
v display LED15. H display LED16. L for display
ED17 is connected. - Commercial AC power is applied to the power supply unit 19 from the terminals 18a and 18b to supply DC power to each part.

(Upper/Lower Limit Value Setting Operation) Next, the operation of the transducer of this embodiment will be described with reference to a flowchart. FIG. 3 is a flow chart showing the operation when setting the upper limit value and lower limit value for providing a relay output from this transducer, and FIG. 4 is a flow chart in the operation mode. When the operation starts, first, in step 21 of FIG. 3, it is checked whether the set mode is set. If the switch SLI is set to the set mode, the process advances to step 22 to check whether the pushbutton switch PB5 is pressed. When this pushbutton switch is pressed, the flag register is updated so that the P flag, H flag, and L flag are set in sequence. Step 23) and step 24.25 proceed to check whether the H flag or L flag is set. Check if. If the H flag is set, the process advances from step 24 to step 26, where the LED 17 is turned off and the LE
D16 is turned on, rHJ is displayed on the panel surface, and the upper limit value setting routine 27 is entered. In this routine 27, the push button switches PBI to PB4 for setting numerical values are used to set the display 6.
The numerical value of each digit is set respectively, and the upper limit value is stored in the H setting value register. When this setting is completed, the process returns to step 21, and it is determined whether or not the set mode is set, and the same process is repeated. When the L flag is set by updating the flag register in step 23, the process proceeds from step 25 to step 28, where the LED 16 is turned off and the LED 17 is turned on to display rLJ on the panel surface. The program then proceeds to a lower limit value setting routine 29, in which the numerical values of each digit of the display 6 are set using the pushbutton switches PBI to PB4 in the same manner as in the routine 27, and the lower limit value is stored in the set value register in the memory. In this way, the process for setting the upper and lower limit values in the set mode is completed.

(Operation in run mode) After setting the upper limit value and lower limit value, press the selector switch SL.
Set I to run mode. The microcomputer 4 of the transducer checks whether it is in the cent mode or run mode in steps 21 and 30. If it is not the run mode, it proceeds to step 21, and if it is the run mode, it proceeds to step 31 and presses the next button. Inputs from button switches PB1 to PB4 are invalidated. Then, in step 32, the data of the model selection switch 5 is read and the input/output specifications are determined in accordance with the data. For example, if the transducer of this embodiment is a transducer that converts an AC voltage of 0 to 150 square meters into a corresponding DC voltage of θ to 5 square meters, then from steps 33 and 34, the respective specifications are set. Set.

Then, the input voltage applied from the input terminals la and lb is rectified by the input Hanofa 2 and raised by /l)'l.

Since the output is applied to the A/D converter 3, the microcomputer 4 gives a predetermined twinning pulse to the A/D converter 3, and the data converted into digital values is sent to the A/D converter 3. It is fetched and written to the PV value register in the memory (step 35).Then, in step 36, it is checked whether the push button switch PB5 has been pressed and changed from off to on.If it has been pressed, the process advances to step 37 and the flag register is written. If the button switch PB5 is not pressed, the process proceeds to step 38 and checks whether the H flag is set. If it has already been stored in the H setting value register, the L limit value is displayed on the display 6, and the LEDs 15 and 174 are turned off, and the LED 16 is turned on to display the 11 setting value (step 39.40). . If the L flag is set in step 41, the lower limit value held in the set value register in the memory is similarly displayed on the display 6 (step 42), and the process proceeds to step 43 where the LEDs 15, 16 off and LED1
7 is lit to display the L setting value. and step 40
Alternatively, the process proceeds from step 43 to step 44 to check whether the PB5 flag is set. Initially, this flag is reset, so the process proceeds to step 45 to check whether the push button switch PB5 has changed from on to off. If the push button switch PB5 is no longer pressed, the process proceeds from step 45 to step 46.4.
7, the PB5 flag is set and an internal timer within the microcomputer 4 is started. This timer is, for example, a timer having a time of 5 seconds. Then, the process returns to step 30 and repeats the same process. Then, when the PB5 flag is determined in step 44 via steps 38 to 40 or steps 41 to 43, the flag is already set, so it is checked in step 48 whether or not the timer has timed up. do. If the time is not up, the display of the upper limit or the lower limit in step 39 or step 42 is continued in step 49, and if the time is up, the timer and the I-35 flag are reset (step 50.51). After pressing the push button switch PB5 during operation and confirming the upper and lower limit values, the display contents can be automatically returned to the current value display without changing to the current value display.

Then, the process proceeds to step 52, where the current value in the pv value register taken in at step 35 is displayed on the display 6, and is also given to the launch circuit 7 to be temporarily held. Then, in step 53, ... E D 16 .

17 is turned off and LED 15 is turned on to display the current value.
The D/A converter 8 outputs a DC voltage of 1-ta0 to 5■ corresponding to the input voltage to the outside from the terminals 9a and 9b (step 54). In step 38 or 41, if the H flag or L flag is not set, the
Proceed to step 2 and perform the processing described above. The program then proceeds to step 49 or step 5431.theta.sub55, where it is checked whether the current value in the register P2 exceeds the set value of the i4 set value register. If the current value does not exceed the FI stage setting il'j, turn off the XH flag, XH relay, and LED 13 in step 56.
), H setting value, is exceeded, the XH flag and the XH relay are turned on in step 57, and the LED 13 is turned on. Then, in step 58, it is checked whether the current value in the PV value register is less than or equal to the L setting value, and if it is not less than the L setting value, the XL flag, XL relay, and LED 14 are turned off in step 59, and the L setting value is If it is below, turn on the XL flag and XL relay.
The ED 14 is turned on (step 60). Then, the process returns to step 30 and repeats the same process.

In this way, it is possible to display the input voltage and obtain a DC linearized output corresponding to the input voltage. Furthermore, the upper and lower limits of the input can be set using two setting value registers, and if the input voltage exceeds the range, It becomes possible to create a transducer that has the function of a meter relay that obtains an output.

Minoru Naoki explained about a transducer that converts AC voltage in a predetermined range into DC voltage, but there are also transducers that can accept different inputs by changing the input cover sofa and the manual power specifications in the operation mode, for example. The present invention can be applied to a transducer that detects alternating current or direct current, or a transducer that converts the temperature of a thermocouple or the like or the output of a tacho generator or the like or the output of a potentiometer into a signal within a predetermined range.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the transducer according to the present invention, FIG. 2 is a front panel view thereof, FIG. 3 is a flowchart showing operation in set mode for setting upper and lower limit values, and FIG. 4 is a flowchart showing operations in run mode. 2-Each buffer 3--A/D converter 4
-・-Microcomputer 5-・-i Type i Selection switch 6-...-Display device ? -------Latch circuit 8-----D/A converter 10--
11---Output bar/nofa XH, XL----Relay
13-17----Light-emitting diode

Claims (2)

[Claims] (1) A transducer that converts an input signal into a corresponding predetermined level signal, including an A/D converter that converts an analog input signal into a digital signal, and upper and lower limits that set the upper and lower limits of the input signal. a value setting means; a storage means for storing the current value and the upper and lower limit values set by the upper and lower limit value setting means; and an input signal A/D converted by the A/D converter and stored in the storage means. a comparison means for comparing the current value with the upper and lower limit values; an output means for outputting an output when the current value exceeds the upper and lower limit values as a result of comparison by the comparison means; and an input that has been A/D converted by the A/D converter. a D/A converter that converts a signal into a signal proportional to its level; a display that displays the upper and lower limits or the current value; and a switching input means that switches the display of the display to the upper and lower limits or the current value. A transducer comprising: control means for switching to displaying the current value after a predetermined time after the switching input means switches and displays the upper and lower limit values. (2) The transducer according to claim 1, wherein the output means includes two relays that are respectively activated when the upper and lower limits are exceeded.