JPH03113379A - Driving method for indicating instrument - Google Patents

Abstract

PURPOSE:To handle a low frequency input and a high frequency input by varying a subtraction period and varying an addition value in inverse proportion to the period. CONSTITUTION:Every time a pulse signal (a) generated by the specific quantity variation of an object of measurement is inputted, a constant value is added to an operand value and a specific value is subtracted at a specific period; and the indication of a display part 3 is determined according to the result and the display part is driven. At this time, the switch 16 of a conversion part 1 compares the arithmetic processing result or the period of the pulse signal with a preset value and sends a switching signal to a timing pulse generation part 12 according to the result. Then the generation part 12 make the arithmetic processing signal period long by increasing the frequency division ratio of reference pulses at the time of the low frequency input to perform the subtraction processing smoothly and also sends the reciprocal signal of the frequency division ratio to a constant generation part 11 to output a division addition signal which is decreased by the extension of the arithmetic processing signal period. For the high frequency input, the arithmetic processing signal period is made short by decreasing the frequency division ratio to perform the subtraction processing speedily and the division addition value is increased in inverse proportion to the arithmetic processing signal period.

Description

[Detailed description of the invention] (Industrial usage W> The present invention relates to a method for driving an indicating instrument.

(Prior art) Indicating instruments that convert the display output from the object to be measured into an appropriate electrical signal (frequency, voltage value, etc.) and operate the pointer of the indicating instrument based on this signal are often used. . Among these, especially in needle holders that require predetermined calculation processing when converting the output of the object to be measured into the meter drive output, there is a conversion section that digitizes the output No. 48 from the object to be measured, and a conversion section that digitizes the output No. 48 from the object to be measured It is equipped with a drive processing section that generates a predetermined drive output in response to a digital signal input from the section, and a display section that receives the drive output and operates the pointer.

Regarding the above-mentioned conversion section, especially in the case of a frequency output that emits a pulse signal every time the measurement target changes by a predetermined amount, such as speed making, it is composed of an F-V conversion section and an A-D conversion section, and the F-V The conversion section often uses a so-called integration circuit that combines a capacitor and a resistor to smooth a pulse signal and convert it into a voltage value, and the Δ-D conversion section converts the voltage value into a digital value corresponding to the voltage value. is output to the next drive processing section.

(Problem to be solved by the invention) F-V in the above-mentioned indicating instrument using digital processing
The converter is composed of a capacitor and a resistor, and since the accuracy of the capacitor varies greatly, it is often seen that the actual output value of the F-V converter differs from the designed output value.

Therefore, we proposed a method for direct digital conversion without performing F-V conversion and A-D conversion (Japanese Patent Application No. 1-1376).
No. 79) This means that a constant value is added to the operand value each time a pulse signal is emitted from the object to be measured, and it corresponds to a certain percentage of the operand value for each fixed period that is emitted regardless of the pulse signal. It performs processing to add a subtracted value or a constant subtracted value, and outputs the processing result (operand value) to the conversion section described above, and the output of this conversion section is a numerical value that balances the addition value and subtraction value. Since the converter output (
The digital numerical value) corresponds to the generation frequency of pulse No. 43 to be measured.

In this frequency digital conversion means, the width of the pulse signal period from the object to be measured is wide, and various inconveniences will occur if the same processing is performed on low frequency input and high frequency input. For example, when the pulse signal period becomes longer, ripples occur in the output of the converter which is the result of arithmetic processing, and the pointer shakes due to this ripple. Next, this pointer deviation will be specifically explained using an example of arithmetic processing using 16 bits (hereinafter expressed as 0000 to FFFF).

Setting conditions, VC? L) ■Subtraction processing formula V (n +1) =” (”)
21〒V(n)i Operand value at any time ■ Subtraction processing cycle T = = 1 msec ■ Value added per 1 input pulse C1 = 0800 ■
The output is the upper 8 bits of the calculation result V(n).

and the input pulse period is 10tn see and IQQm
If the case of 3ee is plotted as a graph, it will be as shown in FIG.

The initial value of I11 is r0OOOJ.

As shown in Figure 4 (a), the input pulse period is 10ff.
In the case of lff1ee, the converter output jumps every 10m5ee, but since the pointer cannot follow this periodic fluctuation,
In reality, the guideline does not shake. In contrast, Fig. 4 (+
The input pulse period as shown in ff) is 100 m sec
In this case, the output of the converter increases every 100 msee, and the pointer of the indicator is driven in accordance with the output of the converter, which naturally causes the pointer to oscillate.

Therefore, as a means to prevent the pointer from shaking during low frequency input,
It is conceivable to perform subtraction slowly by making the addition value small and the subtraction period large. However, when the above-mentioned method is adopted, there is a problem that when a high frequency input pulse signal with a short period is input, sufficient subtraction is not performed and the output of the converter cannot be stabilized. If this is changed, a problem arises in that a continuous constant functional relationship is not established between the calculated processing result and the input frequency of the pulse signal.

(Means for Solving the Problems) The present invention has been made in view of the above-mentioned problems in the means for directly converting the period number input into digital data and using it as a driving reference for a meter, and has proposed an improvement thereof.

In the driving method of the indicating instrument according to the present invention, a pulse signal is emitted every time the object to be measured changes by a predetermined time, a constant value is added to the operand value every time the pulse signal is input, and a predetermined value is subtracted at a predetermined period. In the driving method of the indicating instrument that determines the index of the indicating instrument based on the calculated processing result, the subtraction cycle can be changed, and in response to the change in the subtraction cycle, the addition value is inversely proportional to the subtraction cycle. It is characterized in that it is made by changing.

(Function) As a countermeasure against low frequency input of pulse signals from the object to be measured,
Every time a pulse equal sign is input, a constant value is added to the operand value, and when subtracting a predetermined value at a predetermined period, the subtraction period is lengthened and the subtraction is performed slowly, and the addition value also changes at the subtraction period. If it is changed in inverse proportion to , even if the subtraction period is changed, no change occurs in the functional relationship between the calculated processing result and the input pulse signal frequency. Therefore, whether the input pulse signal is a low frequency input or a high frequency input, the calculation result will be stable.

(Example) Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a block diagram of the entire instrument, FIG. 2 is a detailed diagram of the converter, and FIG. 3 is a graph showing the output of the converter when a low frequency input is applied. +7) shows the state in which the present invention is implemented.

The overall configuration of the indicating instrument consists of a converting section 1. The conversion section 1 is composed of a drive processing section 2 and a display section 3, and when a pulse signal generated according to the operation of the object to be measured is input, the conversion section 1 outputs a digital numerical value according to the pulse frequency, the details of which will be described later. The drive processing section 2 includes an ItOM section 21. D-A converter 22
．． The drive output section 23 is color, and the ROM section 21 stores a digital output corresponding to the output signal (digital numerical value) of the converting section 1 described above, and upon receiving the output of the converting section, outputs the memorized digital numerical value. The next DA converter 22 converts the digital numerical signal into an analog signal and sends it to the drive output unit 23 . The drive output section 23 outputs a drive current for driving the pointer.

In addition, the display section 3 consists of a pointer 1 display board, a drive coil, etc.
It is operated by the drive current from the drive output section 23 described above.

The details of the converter 1 are as shown in FIG.
．． Timing pulse generator 12. Arithmetic unit 1 consisting of latch circuit 13, subtraction value setter 141 and adder 142
4. Adder 15. It consists of a switching device 16. Constant setting 111
consists of a constant generator 111 and a multiplier 2. When the constant generator 111 receives the input of the pulse signal α from the object to be measured, it divides a preset constant value into a predetermined number and outputs the signal from the timing pulse generator 12. The division constant values are sequentially outputted to the multiplication unit 112 in synchronization with calculation process No. 43, and the multiplication unit 112 multiplies the division constant value by a frequency division ratio N from the frequency division unit 122, which will be described later, to obtain the multiplication result. The divided and added values are sent to the adder 15. The timing pulse generator 12 includes a reference pulse generator 1212, a frequency divider 122. Consisting of a processing pulse generator 123, the reference pulse generator 121 generates a reference pulse for the entire circuit, and the division part 122 divides the frequency of the reference pulse into 17H. by. Further, the processing pulse generator 123 outputs arithmetic processing signals to all the circuits in the converter 1.
Each circuit operates on the basis of this arithmetic processing signal. The latch circuit 13 latches the converter output numerical value, and operates 1! ! Output to J14. Arithmetic unit 14 is latched! An addition VB 142 adds a subtraction value determined by a subtraction value setter 141 to the output numerical value from @13, and outputs the result to an adder 15. Adder 15 includes constant setter 11 and adder 141
The output values of the converter 1 are obtained by adding the respective output values. The switch 16 receives the calculation result or the pulse signal input, or both, and issues a switching signal to the frequency dividing section 22. If the input pulse signal is determined to be a high frequency input, the division ratio becomes larger and the g calculation period increases. This is an instruction to make the length shorter.

Next, the above operation will be explained.

First, a case where there is no output from the constant setter 11 will be explained.

The arithmetic processing signal of the timing pulse generator 12 is transmitted to each circuit (
However, the constant setter 11 is excluded), and each circuit performs this process (predetermined arithmetic processing of each circuit in synchronization with No. 1). When this processed signal is output, the latch circuit 13
The operand value held in is output to the subtraction value setter 141 and the addition VB 142 in the arithmetic unit 14. The subtraction value setter 141 is a circuit that sets a value corresponding to a certain percentage of the output operand value as a negative value as a subtraction value, and the adder 142 adds this subtraction value and the operand value. and output to addition@815. The adder 15 is a circuit that adds the operand output from the adder 142 of the arithmetic unit 14 and the constant output from the constant setter 11, but since there is no output from the constant setter 11 at this time, the adder 15, the operand value of the adder 142 is output as is. This output is output to the latch circuit 13 as a new operand value, and this operand value is stored in the ROM section 6 shown in FIG.
Output to.

Therefore, if the above processing is repeated every time the processed signal from the timing pulse generation Pj12 is output, the operand value will become a value that gradually decreases.

Next, the case where there is a numerical output from the constant setter 11, that is, the case where the pulse signal a is input to the converter 1 from the object to be measured will be explained.

When a pulse signal from the object to be measured is input to the constant setter 11 in the converter 1, the constant generator 111 of the constant setter 11
The division constant value is input to the multiplier 112 from , and a predetermined calculation (
(described later) is performed, and the result of the operation (divided addition value) is output to the adder 15, and this divided addition α and the operand value output from the arithmetic unit 14 are added together. Therefore, when a pulse signal is input to the constant setting unit 511, the adder 15 adds the output value of the arithmetic unit 14 and the output value of the constant setting unit 11 at the cycle of the processed signal, and simultaneously performs the above-described subtraction process.

Therefore, the output of the converter 1 becomes a numerical value in which the added value and the subtracted value are balanced.

Next, if the processing result calculated by the switch 16 or the cycle of the input pulse signal becomes too large or smaller than a preset value, the switch 16 sends a switching signal to the timing pulse generator 12. is sent to change the frequency division ratio of the frequency divider 122. In other words, if it is determined that the input is a low frequency input, the division ratio is increased and the processing pulse generator 12
The period of the arithmetic processing signal from No. 3 is lengthened, and the subtraction processing is performed slowly. At this time, the division section 122 sends a reciprocal signal of the division ratio to the multiplication section 112 of the constant generation ill, and the multiplication section 112 multiplies the division constant value from the constant generation section 111 by the reciprocal of the division ratio to increase the period of the arithmetic processing signal. The divided and added value is outputted to the adder 15 with a smaller numerical value corresponding to the difference. Conversely, if the switch 16 determines that it is a high frequency input, the division ratio is reduced, the arithmetic processing signal period is shortened, and subtraction processing is quickly performed, and the division addition value is increased in inverse proportion to the shortened period. It is something to do.

Therefore, in the case of low-frequency input that is particularly prone to pointer wobbling, it is possible to lengthen the subtraction cycle and reduce the added value through a predetermined process, as shown in Figure 3 (B), compared to the same figure (I) in the case of no treatment. ), the output of the converter is more stable and the meter pointer does not shake.

Moreover, it can sufficiently cope with the high frequency input of the Valsico signal, and the output of the conversion section, which is the calculation result, corresponds to the frequency of the input pulse signal.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and the output of the constant setter 11 may not be a divided addition value, but a predetermined addition value may be output once upon input of a pulse signal.

(Effects of the Invention) As described above, when the present invention receives a display pulse signal output from an object to be measured, which is a frequency input, a constant value is added to the input harmonic calculation value, and a predetermined value is added at a constant period. In the method of obtaining the output value corresponding to the frequency input by subtraction and driving the instrument, the subtraction period is changed and
The addition value is changed in accordance with the change in the subtraction period, so that it can correspond to both low-frequency input and high-frequency input of pulse signals.

[Brief explanation of drawings]

Fig. 1 is an overall block diagram of the instrument implementing the present invention, Fig. 2 is a detailed block diagram of the converter, and Fig. 3 is a graph showing the output of the converter when low frequency input is performed. 1 indicates the case where the subtraction period is not changed, (the mark indicates the case where the subtraction period is lengthened. 1 indicates the conversion section l, the constant setter 11, the constant generation section 12, the multiplication section 2, and the timing pulse generator 21, the reference pulse generation section. 122, the frequency divider 123, the processing pulse generator 13, the latch circuit 14, the arithmetic unit 141, the subtraction value setter 142, the adder 15, the adder 16, the switch 2, the drive processing unit 21, the ROM unit 22, D- The A conversion section 23 is the drive output section 3, and the display section

Claims (1)

[Claims] (1) A pulse signal is emitted every time the object to be measured changes by a predetermined amount, and a constant value is added to the operand value every time this pulse signal is input, and a predetermined value is subtracted at a predetermined period, and instructions are given based on the calculation result. A driving method for an indicating instrument that determines the index of the instrument is characterized in that the subtraction cycle is changeable, and in response to the change in the subtraction cycle, the addition value is changed in inverse proportion to the subtraction cycle. A method of driving an indicating instrument.