JPH04111104A - Multi-point controller - Google Patents

Abstract

PURPOSE:To measure with sampling an optional measuring point in the higher frequency than other measuring points by setting an optional point to be measured and a high speed measuring point and inputting the measured values in the order of measuring channels for calculation of a manipulated variable. CONSTITUTION:When the prescribed value is set by a setting means 102 together with a point to be measured and a high speed measuring point, a measuring channel order production means 103 produces a measuring channel order including plural high speed measuring points. This channel order is stored in a storage means 104. A control means 105 switches the measuring channels with a switch means 100 in accordance with the measuring channel order given from the means 104. At the same time, a manipulated variable is operated from the measured value of a switched input measuring channel and the set value and outputted to an output means 101. Then the means 104 stores previously a reference measuring channel order, and a desirable measuring channel is produced according to the reference measuring channel order.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-point temperature controller, for example, a multi-point temperature controller suitable for controlling the temperature of an extruder or the like having a plurality of temperature measurement points. Concerning improvements to controllers.

[Prior Art] Conventionally, this type of multi-point controller 1 has been arranged in correspondence with a plurality of heaters (not shown) arranged in an extruder 3 as a controlled object, as shown in FIG. 9, for example. The measured values PV from the temperature side running sensors 5a to 5n are sequentially switched manually,
From each measurement value PV and preset setting value Sv, for example, PT
It has a configuration that calculates D and outputs the manipulated variable MV to a heater operating device (not shown) in the extruder 3, and the heater current to the heater is controlled by 0N10FF according to the manipulated variable MV. .

In this multi-point controller 1, after measuring the n sensors 5a to 5n, which are measurement points, one by one from the first sensor 5a to the nth sensor 5n, the room temperature and other reference data are measured. It has generally been configured to perform a measurement and then repeat the measurement again starting from the first sensor 5a. That is, the sampling period at each measurement point was equal and fixed.

[Problems to be Solved by the Invention] However, in the extruder 3 in which a plurality of sensors 5a to 5n are arranged, only 1 to 3 specific measurement points among the n sensors 5a to 5n are measured at high speed to extrude. The multi-point controller 1 described above may be used in cases where you want to understand the operating status of the controller 3, or when it is necessary to frequently measure only a specific measurement point but not other measurement points. It was difficult to respond because the order and period were fixed. Examples of the latter include devices that include pressure control functions that require frequent sampling or the like.

In particular, when measuring only specific measurement points, it is necessary to connect a separate dedicated controller to the extruder 3 for measurement.
Not only does this require investment in equipment, but it also has the disadvantage that measurement tends to be complicated.

The present invention has been made to solve these conventional drawbacks, and it is possible to quickly measure any measurement point more frequently than other measurement points among measurement points placed at multiple locations on a controlled object. The objective is to provide a multi-point controller that is possible and reduces cost.

[Means for Solving the Problems] In order to solve such problems, the present invention has the following features: As shown in FIG. It is comprised of a sequence creation means 103, a storage means 1.4, and a control means 105.

The switching means 100 switches measurement channels from a plurality of measurement points arranged on the controlled object 106,
The output means 101 outputs the control target 106 based on the manipulated variable.
The setting means 102 instructs to set predetermined setting values, important measurement points that require measurement among a plurality of measurement points, and high-speed measurement points that increase the measurement frequency.

The measurement channel order creation means 103 is composed of an array corresponding to required measurement points and high-speed measurement points, and creates a measurement channel order in which the high-speed measurement points are arranged a plurality of times in this one-time arrangement. The means 104 stores the set values and the measurement channel order.

Further, the control means 105 switches and controls the switching means 100 in accordance with the order of the measurement channels in the storage means 104, and calculates a manipulated variable from the measurement value and setting value of the measurement channel inputted from the switching means 100, and outputs the above-mentioned output. It is output to means 101.

Moreover, in the present invention, the order of a plurality of reference measurement channels, which are a combination of required measurement points and high-speed measurement points, is stored in advance in the storage means 104, and the order of the reference measurement channels set by the setting means 102 is stored in advance. The measurement channel order creation means 103 can be configured to select the reference measurement channel order according to the measurement point and the high speed measurement point and create the measurement channel order.

[Function] In the present invention equipped with such a means, when a predetermined setting value, a required measurement point, and a high-speed measurement point are set by the setting means 102, the measurement channel order creation means 103 sets the high-speed measurement point. A measurement channel order in which the measurement channels are arranged a plurality of times is created and stored in the storage means 104, and the control means 105 controls switching of each measurement channel by the switching means 100 in accordance with the measurement channel order from the storage means 104. A manipulated variable is calculated from the input measurement value of the measurement channel and the set value, and is output to the output means 101.

In a configuration in which the storage means 104 stores the reference measurement channel order in advance and the measurement channel order creation means 103 selects one of the reference measurement channel orders to create the measurement channel order, the reference measurement channel order is stored in accordance with the reference measurement channel order. A preferred measurement channel order is created.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of a multipoint controller according to the present invention.

In the figure, a measuring circuit 9 arranged in a controlled object 7 such as the extruder 3 in FIG. 9 described above is connected to a multiplexer (
MPX) 11.

The measurement circuit 9 is actually a plurality of sensors as measurement points distributed at a plurality of locations on the controlled object 7, or a heater current detection circuit placed in the middle of a current supply circuit to the heater of the controlled object 7. As will be described later, the multiplexer 11 is a switching means such as a mechanical relay or a semiconductor switch that mechanically or electronically switches the measurement channels from each measurement point in response to a switching signal from the control circuit 13, and the A/D conversion circuit 15 It is connected to the.

The A/D conversion circuit 15 A/D converts the analog measurement value PV of the measurement channel from each measurement point switched by the multiplexer 11 into a digital measurement value PV, and outputs the digital measurement value PV to the control circuit 13.

The control circuit 13 includes, for example, a CPU having a PID calculation function and other known calculation functions, a ROM containing an operation program for the CPU, and an input/output signal interface I.
10, to which a key input circuit 17, an output circuit 19, and a memory circuit 21 are connected.

The key input circuit 17 is under the control of the control circuit 13.
Input the set value S for calculation, the required measurement points that require measurement among the measurement points placed on the controlled object 7, and the high-speed measurement points for high-speed measurement by increasing the measurement frequency among these measurement points, for example, by channel number. In addition to inputting the required measurement points and high-speed measurement points, you can also set the keyboard, etc. to input the required measurement points and high-speed measurement points in order to create a standard measurement channel order that is organized in advance according to the number of required measurement points and high-speed measurement points. means and is located on the main body panel.

The standard measurement channel order is, for example, as shown in Figure 3, the arrangement of each measurement channel for 8 measurement points (measurement channels) is compiled in advance for each high-speed measurement point number from 0 to 7 points. ``Other'' indicates the measurement period for other reference data such as room temperature other than the measurement channel. However, it is also possible to not include the measurement period of other reference data.

In Fig. 3, for example, if there are two high-speed measurement points on the first and second channels, as shown in column A of the figure, the first,
The arrangement includes second, third, first, second, fourth channels, and so on.

Further, FIG. 4 shows the arrangement of each measurement channel for four measurement points (measurement channels) for each high-speed measurement point number from 0 to 3 points.

The order of these reference measurement channels is determined by the key input circuit 17.
Based on the required measurement points and high-speed measurement points input from
It is created in the control circuit 13 and stored in the memory circuit 21 in the form of a list.
is stored in

The output circuit 19 outputs the control target 7 under the control of the control circuit 13.
This is a means for controlling the energization time of, for example, a plurality of heaters arranged in accordance with the operation amount MV from the control circuit 13. However, what is operated by the output circuit 19 is not limited to the heater.

Under the control of the control circuit 13, the storage circuit 21 stores, in addition to the above-mentioned reference measurement channel order, set value Sv, sampling period, measurement channel order, and data on the calculation process and calculation output in the control circuit 13. .

The control circuit 13 has the function of creating the reference measurement channel order as described above, and also inputs the required measurement point (high speed or normal) and high speed measurement point (high speed) input from the key input circuit 17 as shown in FIG. For example, a reference measurement channel order such as that shown in FIG. 6A is read from the memory circuit 21 from among the reference measurement channel orders shown in FIG.
"High speed" designation according to each measurement channel as shown in Figure 5
, “not measured” or “normal” (measures but not fast)
Based on this, it has a function of creating the measurement channel order to be actually read and controlled as shown in FIG. 6B and storing it in the storage circuit 21.

Note that it is not always necessary to designate a "non-measurement" channel, and the setting of a required measurement point in the present invention does not include the designation of "non-measurement."

The control circuit 13 refers to the measurement channel order and controls the multiplexer 11 to switch to obtain the channel measurement value P.
It has a function of inputting V, PID calculating the manipulated variable MV from the deviation from the set value S and outputting it to the output circuit 17.

When the control circuit 13 reads the reference measurement channel order from the storage circuit 21, the control circuit 13 calculates the sampling period of each measurement channel according to the appearance frequency of each measurement channel and stores it in the storage circuit 21, and also calculates the sampling period during PID calculation. Periodic data is read out from the storage circuit 21 and used as a parameter for PID calculation.

That is, the control circuit 13 has a PID calculation function and a switching control function of the multiplexer 11, as well as a measurement channel order creation function and a sampling period calculation function.

Next, the operation of the multi-point controller of the present invention described above will be explained according to the flowcharts of FIGS. 7 and 8.

FIG. 7 shows the procedure for determining the measurement channel order and storing it in the memory circuit 21. This procedure is executed when changing the high-speed measurement point or its number, or when changing the unmeasured channel or its number. be done.

That is, when the program starts, step 20
In step 1, the number of unmeasured channels is counted and substituted for "x", and in step 202, the number n of required measurement points is calculated. This is obtained by subtracting the number of unmeasured channels X from the number of measurement points of the multipoint controller.

In the next step 203, the number of high-speed measurement points is substituted for m, and in step 204, the reference measurement channel order corresponding to the number of required measurement points n and the number of high-speed measurement points m is fetched from the storage circuit 21 (see FIG. 6A), and the following step 205 Now, create the measurement channel order by assigning the actual measurement channels to the imported reference measurement channel order (see Figure 6B).
, is stored in the memory circuit 21.

FIG. 8 shows a procedure related to measurement, which is repeatedly executed while the multipoint controller of the present invention is in operation.

In step 301, the measurement channel order created in step 205 in FIG. For each channel, the multiplexer 11 is turned on and the measured value is inputted, A/D converted, and taken into the control circuit 13.

In the following step 303, the sampling period data of the measurement channel setting value Sv1 of the measurement channel necessary for calculation is read from the storage circuit 21, and in step 304, PID calculation is performed from each data and the measured value PV, and alarm calculation is performed as necessary. Process and output an alarm signal.

Then, steps 301 to 304 are repeatedly executed for the next measurement channel at a predetermined period.

As described above, in the multi-point controller of the present invention, by setting arbitrary required measurement points and high-speed measurement points among the measurement points arranged at a plurality of locations on the controlled object 7 using the key input circuit 17, the pre-created Actual measurement channels are allocated based on the reference measurement channel order, a measurement channel order is created in which high-speed measurement points are arranged more frequently than other important measurement points, and the multiplexer 11 is switched and controlled with reference to this measurement channel order. Input each channel measurement value PV and operate f
It is configured to calculate and output fiMV.

Therefore, by setting only specific measurement points as required measurement points and high-speed measurement points, sampling measurements can be performed at high frequency only at specific measurement points, and some of the required measurement points can be set as high-speed measurement points. For example, other important measurement points can be sampled and measured at a low frequency. That is, in the present invention, the sampling period can be varied.

Moreover, since the measurement channel order is created with reference to the preset reference measurement channel order, if the preferred reference measurement channel order is prepared, the preferred measurement channel order can be created easily and quickly.

Further, the key input circuit 17 of the present invention may be an external communication setting circuit using a communication line, for example, in addition to a keyboard arranged on the main body panel.

By the way, in the multi-point controller according to the present invention, there is an example in which a specific measurement point is designated as a high-speed measurement point from among the measurement points, and the specific measurement point is measured at a higher frequency, that is, at a faster sampling period than other measurement points. However, in the present invention, by focusing on important measurement points other than high-speed measurement points, it is possible to perform low-speed measurement with a long sampling period at a specific measurement point.

Furthermore, in the embodiments described above, all measurement channels had the same content, but the present invention is not limited to this. For example, if some measurement channels are temperature measurement channels,
It is possible to mix different types of measurement channels, such as using another measurement channel as a pressure measurement channel.

[Effects of the Invention] As explained above, the present invention sets arbitrary measurement points and high-speed measurement points among the measurement points arranged at multiple locations on the controlled object, and arranges the high-speed measurement points multiple times at high frequency. The system creates a measurement channel order, references this measurement channel order, switches and controls each measurement channel, inputs the measured value of each channel, and calculates and outputs the manipulated variable. If specified appropriately, it is possible to sample and measure any measurement point among the measurement points placed at multiple locations on the control target at a higher frequency than other measurement points, and the sampling period can also be varied. .

Therefore, when it is necessary to sample and measure specific measurement points at high frequency, for example, when measuring only 1 to 3 measurement points at high speed to understand the operating status, or when the control target is different and high-speed sampling is required. When controlling a controlled amount, there is no need to use a separate dedicated controller, so expensive equipment investment can be reduced.

Furthermore, in the configuration in which the measurement channel order is created by the measurement channel order creation means from the reference measurement channel order in which the required measurement points and high-speed measurement points are stored in the storage means, it becomes possible to create a preferred measurement channel order easily and quickly.

[Brief explanation of drawings]

FIG. 1 is a claim correspondence diagram of a multi-point controller according to the present invention, FIG. 2 is a block diagram showing an embodiment of a multi-point controller according to the present invention, and FIGS. 3 and 4 are the same as those in FIG. 5 and 6 are diagrams illustrating the measurement channel order creation operation according to the present invention. FIGS. 7 and 8 are detailed explanations of the present invention. FIG. 9 is a schematic diagram showing the configuration of a multipoint controller and a controlled object. 1・・・・・・・・・・・・Multi-point controller 3.7・
......Controlled objects 5a to 5n...Measurement points (sensors)

Claims (2)

[Claims] (1) A switching means for switching measurement channels from a plurality of measurement points arranged on a controlled object, an output means for controlling the control object based on a manipulated variable, and a predetermined setting value and a plurality of measurement points arranged at the plurality of measurement points. A setting means for setting important measurement points that require measurement and high-speed measurement points that increase the measurement frequency, and an array corresponding to the necessary measurement points and high-speed measurement points, and a setting means for setting the high-speed measurement points in the array for each time. Measurement channel order creation means for creating a measurement channel order arranged multiple times; Storage means for storing the set value and measurement channel order; Switching control of the switching means in accordance with the measurement channel order of the storage means. and control means for calculating a manipulated variable from the measurement value of the measurement channel inputted from the switching means and the setting value and outputting it to the output means. (2) The storage means stores in advance a plurality of reference measurement channel orders obtained by combining these in correspondence with the numbers of the required measurement points and high-speed measurement points, and the measurement channel order creation means is configured to store a plurality of reference measurement channel orders in accordance with the numbers of the required measurement points and high-speed measurement points, and the measurement channel order creation means 2. The multi-point controller according to claim 1, wherein the reference measurement channel order is selected in accordance with the required measurement point and the high-speed measurement point set by the reference measurement channel order to create the measurement channel order.