JP3040533B2 - Digital indicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital indicator used when a process measurement value of a plant control is digitally displayed.

[0002]

2. Description of the Related Art FIG. 3 is a perspective view showing a conventional digital indicator. In FIG.
A segment LED display unit, 9 is a unit display unit, and 4 is a main body chassis. FIG. 4 is a functional block diagram of the digital indicator. Reference numeral 5 denotes an input signal A / D converter, and reference numeral 7 denotes a numerical value display drive unit.

Next, the operation will be described. The process measurement signal output from the sensor or the converter is transmitted through a signal input cable 1 such as optical, coaxial, or twisted pair.
It is input to the digital indicator in the form of a signal such as a BCD code or 1-5 V, 4-20 mA. This process measurement signal is digitized by the A / D converter 5 in the main body chassis 4 and displayed on the 7-segment LED display 2 through the numerical display drive 7. The unit display section 9 is for recognizing a unit of a numerical value displayed on the 7-segment LED display section 2, and is usually engraved or printed on the front surface of the main body chassis 4, or printed on an acrylic plate or the like. The unit name is displayed on the backlight.

[0004]

Since the conventional digital indicator is configured as described above, the process measurement signal is individually input for each measurement engineering unit, so that the unit display on the front of the main body chassis 4 is displayed. Part 9 had to be prepared at the hardware level for each measurement engineering unit. Therefore, 2
There is a problem that a single digital indicator cannot cope with a display request of a double unit or a triple unit.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. The hardware of one digital indicator can respond to the display of measured values of all measurement loops, and one digital indicator can be used. It is an object of the present invention to obtain a digital indicator capable of displaying measured values of a plurality of units.

[0006]

A digital indicator according to the present invention is configured to input a signal consisting of a measured numerical value and a unit code indicating the unit name. The unit code is separated from the unit code, the unit name corresponding to the separated unit code is obtained from the correspondence column table, and the unit name and the separated numerical value are displayed on respective display means.

[0007]

The digital indicator according to the present invention can display measured values of all engineering units with one piece of hardware, and can display a plurality of units such as double, triple, and the like.

[0008]

[Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes an input signal cable for simultaneously transmitting a process measurement signal and a unit code indicating the unit name, and 2 denotes a numerical value of the process measurement signal.
A segment LED display unit 3, a dot matrix display unit 3 for displaying a numerical unit, and a reference numeral 4 are a main body chassis in which a display drive unit and the like are housed.

FIG. 2 is a functional block diagram of the digital indicator. In FIG. 2, reference numeral 5 denotes an A / D converter for converting an analog input signal (1-5 VDC, 4-20 mA DC, etc.) into a digital signal, and reference numeral 6 denotes a numerical value and a unit code of the process measurement signal input through the input signal cable 1. Numeral / unit separation unit 7 for separating the numerical value and the unit code from the mixed digital signal of the above, inputs the separated numerical signal, and causes the 7-segment LED display unit 2 to display it as a process measurement value. A drive unit for displaying numerical values, 8 is a unit display drive unit including a microcomputer for inputting the separated unit codes and displaying the units on the dot matrix display unit 3, and 8a is a unit code for unit codes and unit names. It is a ROM as a storage unit in which a one-column correspondence table is stored.

The 7-segment LED display section 2 and the numerical display drive section 7 constitute numerical display means. The dot matrix display unit 3 and the unit display drive unit 8 constitute a unit display unit.

Next, the operation will be described. The signal input cable 1 simultaneously inputs a process measurement signal and a unit code from an intelligent sensor having an ability to transmit not only a process measurement signal, but also a measurement unit, a parameter of the sensor itself, a host controller, and the like to the digital indicator. At this time, the form of this input signal is 1-5 VDC,
In the case of a system in which a unit code signal is mixed on an analog signal such as a 20 mA ADC or the like, it is digitally encoded through an A / D converter 5 and input to a numerical value / unit separator 6. If the signal form is a digital communication system from the beginning, such as optical digital transmission, it is directly input to the numerical / unit separation section 6.

In the numerical value / unit separation section 6, the input digital signal is separated into a numerical value of a process measurement signal and a unit code by a built-in microcomputer.
The separated numerical signal is displayed on the 7-segment LED display unit 2 through the numerical display drive unit 7. On the other hand, the separated unit codes are displayed on the dot matrix display unit 3 through the unit display drive unit 8. At this time, the unit display drive unit 8 has a ROM 8a having a table corresponding to a unit code and a unit name. The input unit code and the table corresponding to the ROM 8a are associated with each other, and the unit name is determined by a microcomputer. To judge. This will display the correct unit name.

Embodiment 2 FIG. In the first embodiment, the dot matrix display unit 3 is used as the unit display means, but a liquid crystal display may be used. Also, in the first embodiment, the numerical display means is provided with a 7-segment LE.
D display unit 2, dot matrix display unit 3 as unit display means
However, the same effect can be obtained by using a dot matrix or a liquid crystal display for all display means.

Embodiment 3 FIG. In the first embodiment, the dot matrix display unit 3 is used for unit display. However, if the unit code signal is changed to, for example, an alarm code signal or a message code signal, alarm and message information are displayed. It is possible.

[0015]

As described above, according to the present invention, a signal consisting of a measured numerical value and a unit code indicating its unit name is input, and the numerical value and the unit code are input from this input signal. And the unit name corresponding to the separated unit code is obtained from the corresponding one column table, and the unit name and the separated numerical value are displayed on the respective display means. By inputting both at the same time, there is an effect that display of all measurement engineering units can be performed by one digital indicator.

[Brief description of the drawings]

FIG. 1 is a perspective view of a digital indicator according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of a digital indicator according to one embodiment of the present invention.

FIG. 3 is a perspective view of a conventional digital indicator.

FIG. 4 is a functional block diagram of a conventional digital indicator.

[Explanation of symbols]

 2 7-segment LED display unit (numerical display unit) 3 dot matrix display unit (unit display unit) 6 Numerical / unit separation unit 7 Numerical display drive unit (numerical display unit) 8 Unit display drive unit (unit display unit) 8a ROM (storage unit)

Claims (1)

(57) [Claims] 1. A numerical value / unit separating unit for separating a numerical value and a unit code from an input signal including a measured numerical value and a unit code indicating a unit of the numerical value, and a numerical value / unit separating unit separating the numerical value and the unit code. Numerical value display means for displaying a numerical value, a storage unit storing a one-column table of the correspondence between the unit codes and the unit names, and a unit name indicated by the unit code separated by the numerical / unit separating unit in the one-column correspondence A digital indicator comprising: a unit display means for obtaining a unit name from a table and displaying the unit name.