JPH089555Y2 - Air conditioning control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a device for controlling air conditioning in a room of a building, and more particularly to an improvement for easily accessing a detection end or an operation end.

<Prior Art> FIG. 5 is a configuration block diagram of a conventional air conditioning control device. Here, each device is arranged in a hierarchical structure, and the uppermost layer has an OPS (operator's station) in charge of a man-machine interface and a printer PRT.
The layer is MCS (master control station), the third layer is LCS (local control station), and the fourth layer is IOM (input / output module). Some IOMs are in charge of contact output and others are in charge of analog input / output, and have a function as a single-loop controller as needed. A sensor that detects temperature and humidity, an actuator that adjusts the valve opening, and the like are attached to the tip of the fourth layer. If necessary, the first to third layers are integrated to have a scale that matches the control target.

In the field installation work of such a device, the set value of the controller is a value that is predetermined in terms of environmental engineering. Moreover, the values of the detector are also displayed so that the correct temperature and humidity are displayed.

<Problems to be solved by the device> However, the location of the detector is strictly different from the location of the worker. Since the purpose of air conditioning is to provide an environment in which workers can work comfortably, it may be necessary to appropriately correct the detection value of the detector (for example, in a well-ventilated place, ventilation is necessary for ventilation). Feeling temperature decreases). In this case, conventionally, the offset adjustment terminal of the detector is used for adjustment. However, the detectors are distributed in various places, and this adjustment work is complicated. In addition, the detector also had to be provided with an offset adjustment terminal, which made the configuration complicated (for example, in a thermometer using a resistance thermometer pair, the resistance value of the bridge was adjusted). ).

The present invention solves such a problem, and an object of the present invention is to provide an air conditioning control device in which the offset can be easily adjusted and the detector configuration is simple.

<Means for Solving the Problems> The present invention that achieves such an object is provided by connecting one-to-one with a plurality of measuring terminals 10 that generate electric signals corresponding to measured quantities such as temperature and humidity. An input circuit 20 for generating a voltage signal corresponding to the signal, a multiplexer unit 30 for inputting a signal output from the input circuit to a predetermined channel and outputting a signal corresponding to a predetermined measuring end to a selected part, and An analog-digital converter 40 that converts the voltage signal output from the multiplexer unit into a digital signal of a predetermined number of digits, a conversion table unit 50 that stores the relationship that converts the voltage signal into each of the measurement quantities, and each of the measurement terminals An offset table unit 60 that stores an offset value that is a deviation between a measured value and a value felt by an employee, and a conversion table unit that converts the digital signal into the measured amount. An air conditioning control device comprising a control unit 70 for adding an offset amount corresponding to the input circuit of the offset table section, wherein the control unit sends a switching signal CHSEL to the multiplexer section and corresponds to the switched channel. It is characterized in that the items in the conversion table section are referred to.

<Operation> Each component of the present invention has the following operation. The input circuit is provided for each measuring end and generates a voltage signal corresponding to the measured value. The multiplexer unit switches which measurement signal to process. The analog-digital converter converts an analog signal output from the multiplexer unit into a digital signal to facilitate signal processing. The conversion table unit converts the read digital signal into a measurement value, and the calculation time is shortened by forming a table. The offset table section fills the gap between the value at the measuring end and the value desired by the employee. The control unit corrects the measurement value obtained in the conversion table section with the data in the offset table section, obtains the measurement value, and operates as a controller.

<Embodiment> The present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a constitutional block diagram showing a first embodiment of the present invention. In the figure, the measuring end 10 is a resistance temperature detector here and is of a three-wire type. The input circuit 20 is a circuit for obtaining the resistance value of the resistance temperature detector, and obtains the resistance value from the voltage generated by supplying a constant current. The multiplexer unit 30 receives the voltage signals of the plurality of input circuits 20 and outputs any one of the signals based on the selection signal CHSEL. The amplifier 35 amplifies the signal output from the multiplexer unit 30 by a predetermined value.
The analog-digital converter 40 converts the signal output from the amplifier 35 into a digital signal, and switches between the conversion mode and the transmission mode for outputting the conversion result by the control signal ADCNT. The conversion table unit 50 stores a relationship for converting the data converted by the analog-digital converter 40 into an actual measurement value. For example, in the case of a resistance temperature detector, the resistance value is expressed by a cubic expression of the temperature, so that The calculation time is shortened by calculating the relationship and enabling the calculation by a simple proportional calculation. Normally, this data is provided by an external device according to the type of RTD. The offset table unit 60 provides the deviation between the value measured by the measuring end 10 and the value felt by the employee, and is set to be one-to-one for each measuring end 10. The control unit 70 refers to the exchange table section 50 and the offset table section 60 for the data converted by the analog-digital converter 40 to obtain a measurement value, and sends a control signal to an actuator such as a valve in a direction matching the set value. It has a controller function and also exchanges data with external devices via a communication line.

FIG. 2 is a block diagram showing the details of the resistance temperature detector and the input circuit 20, and only one circuit is shown here. Measuring end 10
Is a resistance temperature detector R, a reference resistance Ro and a copper wire resistance r.
The input circuit 20 has switches S1 to S4, a constant current source I, and a circuit for outputting a voltage to the amplifier 35. Voltage selection signal VSEL
Selects the case where the resistance value of the resistance temperature detector R is measured and the case where the resistance value of the reference resistance Ro is measured and calibrated by appropriately switching the switches S1 to S4.

This operation will be described below. The switches S1 to S4 are selectively turned on, and their output voltages are V1 to V4, respectively. Assuming that the input impedance of the amplifier 35 is very high, the voltages V1 to V4 are given by the following equations.

V1 = (Ro + 2r + R) I (1) V2 = (Ro + r) I (2) V3 = RoI (3) V4 = 0 (4) From the above equations (1) to (3), the following equation is established.

R / Ro = (V1−2V2 + V3) / V3 (5) If the reference resistance Ro is a highly accurate resistance, the resistance value R of the resistance temperature detector can be obtained with high accuracy.

Second Embodiment FIG. 3 is a configuration block diagram showing a second embodiment of the present invention. In the figure, the measuring end 10 has a current signal (for example, 0 to 20).
mA, 4 to 20 mA), voltage signals (for example, 0 to 5 V, 1 to 5 V), and resistance temperature detectors. The input circuits 20 are provided in a one-to-one correspondence with the type according to the type of the measuring end 10. FIG. 4 is a circuit diagram showing the details of the input circuit 20, in which (A) is a resistance temperature detector,
(B) represents a voltage input, and (C) represents a current input. In FIG. 4 (C), the current signal is converted into a voltage signal by the voltage conversion resistor R. The input mode signal INCNT is supplied only to the input circuit 20 for the resistance temperature detector, and the voltage selection signal VS
Equivalent to EL. The programmable amplifier 36 is provided in place of the amplifier 35 and has a control unit.
The amplification factor is determined by the gain adjustment signal PGACNT supplied from 70. This gain is determined by switching the resistance, for example. Thereafter, the output of the programmable amplifier 36 is sent to the analog-digital converter 40 and converted into a digital signal. The gain is chosen so that the digital conversion is performed with sufficient precision. Since the operation thereafter is the same as that of the first embodiment, the description thereof will be omitted.

Next, how to obtain the measured voltage will be described. The reference voltage is Vs, the ground voltage is Vg, and these AD conversion results are Xs and Xg, respectively. Then, the AD conversion result of the measured value is X
The voltage V of the measured value is given by the following equation.

V = (Vs-Vg) (X-Xg) / (Xs-Xg) In the case of current input, it may be divided by the conversion resistance R.

<Effect of Device> As described above, the present invention has the following practical effects.

The offset table section 60 is provided and the conversion table section 50 is provided.
Since the value of is corrected, the offset can be easily adjusted and individual settings can be easily performed according to the work environment of each worker. Further, since there is no offset adjustment terminal on the detector side, the structure of the measuring end 10 is also simplified.

If a high-precision analog-digital converter 40 is used and a high-precision and high-stability resistor is used as the reference resistance Ro as in the first embodiment, the number of adjustment points is reduced and the measurement operation becomes easier.

When the programmable amplifier 36 is provided and the gain is adjusted according to the accuracy of the analog-digital converter 40 as in the second embodiment, a high-resolution measurement result can be obtained.

[Brief description of drawings]

FIG. 1 is a structural block diagram showing a first embodiment of the present invention, FIG. 2 is a structural block diagram showing details of a resistance temperature detector and an input circuit 20, and FIG. 3 is a second embodiment of the present invention. FIG. 4 is a block diagram showing the configuration of the input circuit 20. FIG. 5 is a configuration block diagram of a conventional device. 20 ... Input circuit, 30 ... Multiplexer, 40 ... Analog-digital converter, 50 ... Conversion table, 60 ...
Offset table section, 70 ... Control unit.

Claims (1)

[Scope of utility model registration request] 1. A one-to-one connection with a plurality of measuring terminals (10) for generating electric signals corresponding to measured quantities such as temperature and humidity,
An input circuit (20) for generating a voltage signal corresponding to this electric signal and a multiplexer section for inputting a signal output from the input circuit to a predetermined channel and outputting a signal corresponding to a predetermined measuring end to a selected part. (30), an analog-digital converter (40) for converting the voltage signal output from the multiplexer unit into a digital signal having a predetermined number of digits, and a conversion table unit for storing the relationship for converting the voltage signal into each of the measured quantities. (50) and an offset table section (6) for storing an offset value which is a deviation between a value measured at each of the measuring ends and a value sensed by an employee.
0), and a control unit (70) for adding an offset amount corresponding to the input circuit of the offset table unit when the digital signal is converted into the measured amount using the conversion table unit. An air conditioning control device, wherein the control unit sends a switching signal (CHSEL) to the multiplexer unit and refers to an item of the conversion table unit corresponding to the switched channel.