JPS59122924A - Pressure measuring device - Google Patents

Abstract

PURPOSE:To make it possible to rewrite memory, by providing a memory for storing processing parameters, a read only memory for storing key words and processing procedures, and a switch with a lock; and inputting specified external data from the switch with the lock. CONSTITUTION:A nonvolatile memory 11, which can be electrically written and read, is used for storing processing parameter. Rewriting and inhibiting procedures for the memory 11 are performed by On and OFF of a switch with a lock 12 and, e.g., a key word of CALBcr. In this constitution the following merits are provided: the processing parameters are not evaporated by the stop of power from a power source; the processing parameters are not damaged by erroneous operation; a lid of equipment is not required to open in changing the processing parameters in the nonvolatile memory 11; and the possibility that thermal balance in the equipment is lost and temperature correcting parameter cannot be obtained can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a pressure measuring instrument that performs correction processing such as linearization and temperature correction using a micro-scaler.

[Technical background of the invention and its problems]

With the development of microprocessors, microprocessors are increasingly being used for signal processing in various Zorothes measuring instruments. Conventionally, a pressure measuring device using such a microprocessor has a pressure detection circuit 1 that detects pressure and converts it into a digital signal, a temperature detection circuit 2, a microprocessor 3, and a memory for signal processing procedures, as shown in FIG. A measuring instrument main body 7 is constituted by a first non-volatile memory dedicated to the processing, a second non-volatile read-only memory 15 for storing processing parameters, and an input/output circuit 6. Data is exchanged with an external device (for example, a V process control device) 8 via the output circuit 6. In this measuring instrument main body 7, the microprocessor 3 stores first and second dedicated memories 4, 5.
Performs necessary processing of the pressure detection signal of the pressure detection circuit 1 based on the processing procedure and processing meter, and
Since the pressure detection circuit 1 has temperature dependence, the temperature detection signal from the temperature detection circuit 2 is taken in, and in addition to the above processing, correction processing for the nonlinearity of the pressure detection circuit 1 is performed, and the data after the correction is input. It is applied to an external device 10 via an output circuit 6. Note that the first and second dedicated memories 4 and 5 are non-volatile because it is necessary to store programs such as processing procedures for an appropriate period of time, and because it is difficult to constantly supply power. ROM is used. In the figure, P
indicates pressure, and T indicates temperature.

By the way, in a pressure measuring device that processes data using the microprocessor 3, data processing is performed by the microprocessor 3 while taking into account the individual differences of the device, so-called instrumental differences, during manufacturing and calibration of the device. . For this reason, the second dedicated memory 5 has a removable structure as shown in FIG. 2, so that it can be removed when necessary, rewritten the processing parameters, and then inserted back into the predetermined position. However, this series of work to rewrite parameters and parameters is complicated9, and furthermore, since the lid 8 has to be opened to remove the memory 5, the thermal equilibrium state inside the device is different from that during use, and temperature correction is required. There is a drawback that processing accuracy is lost.

[Purpose of the invention]

The present invention makes it possible to rewrite the processing parameter without opening the lid of the equipment, maintains a thermal equilibrium state in the circular part of the equipment, and prevents the meter under the processing from volatilizing due to erroneous operation. An object of the present invention is to provide a pressure measuring device using a microprocessor that allows easy operation.

[Summary of the invention]

The present invention provides electrical readout for storing process parameters;
It has a writable memory, a read-only memory that stores keywords and processing procedures, and a lock switch, and when data matching the keyword is input from an external device and specific data is input from the lock switch (power). This is a pressure measuring device that, when input, can read and rewrite the memory that can be filled according to the processing procedure described above.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG. In these figures, the same parts as in Figs. 1 and 2 are given the same reference numerals, and detailed explanations are omitted.The first point is that this pressure measuring instrument is different from conventional ones. In place of the conventional second dedicated memory 5, for example, an electrically readable and writable EEP-ROM (Electrical Er
A non-volatile memory 11 such as aaaable-pgoM) is provided, and processing parameters can be stored and retained in this.

This EEP-ROM is, for example, Intel's 2
816EEP-ROM is used. Second, a lock switch 12 is provided in the microprocessor 3, and when the lock switch 12 is set to a predetermined switching state, for example, when the switch is turned on, a key 13 is used to issue a command to the microprocessor 3 to rewrite data in the nonvolatile memory 11. To give. Third, a nonvolatile read-only memory 4' such as a ROM for storing processing procedures is provided, a series of predetermined data (keywords) A is stored in this memory, and further input/output from external equipment (e.g., process control equipment) 10 is provided. When the series of data received through the circuit 6 and the series of data A match and the lock switch 12 is turned on at that time, the data in the non-volatile memory 11 can be rewritten; otherwise, the data can be rewritten. This is because the processing procedure B'ft, which prohibits rewriting, is stored. Note that the series of data A to be stored and held in the non-volatile read-only memory 4' is, for example, CALB cr in ASCII code.
A series of codes (cr: carriage return) are used to prevent processing parameters from being changed due to erroneous operations. Further, the lock switch 12 is attached to the panel surface 7a of the measuring instrument main body 7, as shown in FIG.

Next, the operation of the pressure measuring device constructed as described above will be explained. The pressure detection circuit 1 detects the pressure P, converts it into a digital pressure detection signal, and supplies it to the microprocessor 3.

The temperature detection circuit 2 similarly detects the temperature T, converts it into a digital temperature detection signal, and then supplies it to the microprocessor 3. Here, the microphone o 7' o processor 3 follows the preprocessing procedure of the nonvolatile read-only memory 4'.
And processing of non-volatile memory 11? After reading out the pressure detection signal and performing processes such as linearization and temperature correction, the pressure detection signal is transmitted to the external device 10 via the input/output circuit 6.

Next, when calibrating the device, the measuring device main body 2 is installed in a constant temperature bath, and the measuring device main body 7 is equipped with external equipment 10 including, for example, a reference pressure generator for calibration, a temperature control device, and a control conbeater. Calibration equipment is connected. Then, a predetermined temperature and a reference square are applied to the measuring instrument main body 7 by the control computer. At this time, the key 13 is inserted into the lock switch 12 to turn on the lock switch 12 to enable rewriting of data, and a series of data such as a CALBcr code is sent from the control computer. This series of codes is input to the microprocessor 3 via the input/output circuit 6. When a series of data is input from an external device 10, the microprocessor 3 stores the data and the nonvolatile read-only memory 4.
' is compared with the series of data A, and if they match, the write command from the lock switch 12 is sent to the non-volatile memory 11 based on the processing procedure B of the dedicated memory lJ4/.
It is determined that p change is permitted. Then, the microprocessor 3 determines a meter for processing so that the sword data of the device becomes the correct value, and rewrites the processing value and the meter in the non-volatile memory 11. In practical terms,
By performing the calibration for each pressure and temperature, processing parameters such as linearization and temperature correction are optimized and calibration is completed. After the calibration, the lock switch 12 is turned off, and according to processing procedure B, rewriting of data in the nonvolatile memory 11 is prohibited, and the memory 11 stores and holds the calibrated processing parameters.

Therefore, according to the configuration of the embodiment as described above, the processing no.
A non-volatile memory 11 that can be electrically read/written is used to store the parameters, and a switch 12 with a force/lock is used.
Since the processing procedure for rewriting and prohibiting the memory 11 is performed by turning on/off and using the keyword CALB cr, for example, the processing parameters will not be volatile due to power supply interruption, but also will not be affected by erroneous operation. There is no possibility that the processing noclameter will be destroyed. Moreover, since the non-volatile memory 11 can be electrically written, there is no need to open the lid 8 of the device even when changing the processing parameters during calibration, for example, and the thermal equilibrium of the device circle is disrupted. There is no need to worry about not being able to obtain temperature correction/parameters.

In the above embodiment, the ASCII code CALBcr was used as the keyword, but it is also possible to use a character string or a binary code that cannot be used for normal data exchange (it goes without saying. For example, an electronic switch circuit 2 may be used instead of the lock switch 12, and when this switch circuit is turned on a predetermined number of times, it will be a rewrite command, or a code signal consisting of an on/off force may be used. It may also be interpreted as a key change command.!, ta, a lock switch with a lid, or chi.In addition, the present invention can be implemented with various modifications without departing from the gist thereof.

〔Effect of the invention〕

As described in detail above, according to the present invention, an electrically readable and rewritable memory is used for storing processing/f parameters, and rewriting of this memory is protected by a lock switch and a keyword. Therefore, the processing parameters will not be destroyed due to incorrect operation, and the processing parameters can be changed without opening the lid of the equipment. It is possible to provide a pressure measuring device that can perform calibration while maintaining its state, and can therefore ensure accuracy in temperature correction.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram of a conventional pressure measuring device, FIG. 2 is a diagram of the internal state of the device when the lid is opened, and FIG. 3 is a block configuration diagram showing an embodiment of the pressure measuring device according to the present invention. FIG. 4 is a conceptual diagram showing the external appearance of the device. 1...Pressure detection circuit, 2...Temperature detection circuit, 3...
・Microglosse, 4'...Nonvolatile read-only memory, 6...I/O circuit, 7...Measuring instrument body, 1
0...external device, 1no...nonvolatile memory, 12.
・Switch with lock. Fang 1 illustration Fang 2

Claims (1)

[Claims] A pressure measuring instrument in which a microprocessor performs correction processing of a pressure detection signal detected by a pressure detection circuit based on a detected temperature includes a human-debra circuit that controls data exchange between the microprocessor and an external device, and a necessary a lock switch that gives a command to the microprocessor to rewrite processing parameters; and an electrically readable and writable non-volatile device connected to the microprocessor that stores the processing parameters necessary for the correction processing and other data processing. a non-volatile read-only memory connected to the microprocessor and storing keywords, processing procedures, etc., and a predetermined data input from the external device in the microprocessor and the keyword match, and and means for making the nonvolatile memory rewriteable according to the processing procedure when a processing parameter rewriting command is issued from the arm switch, and changing the processing parameter according to data from the external device. Features: Pressure measuring device.