JP3431366B2 - Analog setting signal input circuit of motor controller - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit incorporated in a motor control device, the motor control device having a function of converting an analog setting signal (for example, a speed setting signal) given from the outside into a digital signal. Of the analog setting signal input circuit.

[0002]

2. Description of the Related Art An example of an analog setting signal input circuit of such a motor control device is shown in FIG. In FIG. 9, two voltage dividing resistors 3 and 4 are connected in series as voltage detecting resistors between an input terminal 1 for inputting an analog setting signal given from the outside and a common terminal 2. , The jumper pin 5 and the current detection resistor 6 are connected in series. The jumper pin 5 is separated 2
It has a number of pins, and when a short-circuit component (not shown) is mounted, the two pins are short-circuited. A capacitor 8 forming a filter 7 and an input terminal of an A / D converter 9 are connected between the terminals of the voltage dividing resistor 4 on the common terminal 2 side.

In the above structure, when an analog voltage setting signal is input, the jumper pin 5 is kept in a state in which no shorting part is mounted. When an analog voltage setting signal is input to the input terminal 1 in this state, the voltage setting signal is divided by the voltage dividing resistors 3 and 4 and falls within the input voltage range of the A / D converter 9. Subsequently, this divided voltage signal is subjected to noise removal by passing through the filter 7, and then input to the A / D converter 9 and A / D converted. The A / D converted digital signal is applied to the CPU of the motor control circuit.

On the other hand, when an analog current setting signal is input, a short-circuit component is attached to the jumper pin 5 to make a short circuit. When an analog current setting signal is input to the input terminal 1 in this state, the current setting signal is applied to the current detection resistor 6
And a voltage is generated between the terminals of the current detecting resistor 6.
Subsequently, this voltage is divided by the voltage dividing resistors 3 and 4, and after passing through the filter 7, is input to the A / D converter 9 and is A / D converted. In this case, the resistance values of the voltage dividing resistors 3 and 4 are set to values considerably larger than the current detecting resistor 6, and the current input impedance is substantially equal to the resistance value of the current detecting resistor 6.

[0005]

In the above conventional configuration, the jumper pin 5 is used to switch between the case of inputting the voltage setting signal as the analog setting signal and the case of inputting the current setting signal. Therefore, the number of mechanical contacts is increased, so that the reliability of the device is lowered. In addition, since the short-circuit component of the jumper pin 5 is mounted or removed at the time of switching the input, the short-circuit component may be accidentally dropped in the case of the motor control device. In this case, the electric circuit arranged in the case may be short-circuited or damaged. Further, when the input switching is erroneous, for example, when the voltage setting signal is input to the input terminal 1 in a state where the jumper pin 5 is short-circuited, a relatively large current flows because the current detection resistor 6 has a small resistance value. , Voltage setting signal source and A / D converter 9
There was a risk of damage.

Therefore, an object of the present invention is to improve the reliability of the device by not using the jumper pin for input switching, and to prevent the device from being damaged during switching by not using the input switching work. An object is to provide an analog setting signal input circuit of a motor control device that can prevent switching from occurring.

[0007]

An analog setting signal input circuit of a motor control device of the present invention comprises a voltage signal terminal for inputting an analog voltage setting signal, a current signal terminal for inputting an analog current setting signal, and A voltage detecting resistor connected between the voltage signal terminal and the common terminal, a current detecting resistor connected between the current signal terminal and the common terminal, the current signal terminal and the voltage signal terminal A first diode connected between the voltage signal terminal and blocking the current flowing from the voltage signal terminal to the current input resistor; and A between the terminals of the voltage detection resistor for A / D conversion.
It is characterized by including a / D converter.

According to the above means, when the analog setting signal is the voltage setting signal, the voltage setting signal may be input to the voltage signal terminal. In this case, the voltage setting signal appears as a terminal voltage of the voltage detection resistor, and the terminal voltage is A / D converted by the A / D converter. Here, even if the voltage setting signal tries to flow from the voltage signal terminal toward the current detecting resistor, it is blocked by the first diode, so that the voltage setting signal source is not damaged.

On the other hand, when the analog setting signal is the current setting signal, the current setting signal may be input to the current signal terminal. In this case, the current setting signal flows through the current detecting resistor to generate a terminal voltage of the current detecting resistor, and the terminal voltage is A / D converted by the A / D converter. Here, the current setting signal flows to the voltage detection resistor side, but the current does not flow too much because the resistance value of the voltage detection resistor is large. Further, since the current from the current setting signal source is a constant current, too much current does not flow and the current setting signal source is not damaged. And according to the said structure, the jumper pin for input switching becomes unnecessary, and input switching work becomes unnecessary.

In the above structure, it is preferable to connect a second diode that allows a current flowing from the current signal terminal to the current detecting resistor between the current signal terminal and the current detecting resistor. According to this configuration, the forward voltage drop and temperature drift of the first diode can be canceled or reduced by the second diode. Further, connect the first diode and the second diode to 1
It may be configured by individual transistors.

On the other hand, an analog setting signal input circuit of another motor control device of the present invention includes a voltage signal terminal for inputting an analog voltage setting signal, a current signal terminal for inputting an analog current setting signal, and the voltage signal. A / D conversion is performed by inputting a plurality of voltage detection resistors connected in series between the terminal and the common terminal and the inter-terminal voltage of the resistors on the common terminal side among the plurality of voltage detection resistors. An A / D converter is provided, and the current signal terminal is connected to an intermediate connection point of the plurality of voltage detection resistors. Even with this configuration, the jumper pin for input switching can be dispensed with and the input switching work can be dispensed with.

Further, in the case of the above configuration, a third portion for blocking the current flowing from the voltage signal terminal to the current signal terminal between the current signal terminal and the intermediate connection point of the plurality of voltage detecting resistors.
It is preferable that the diode is connected. According to this configuration, it is possible to reliably prevent the current from flowing from the voltage signal terminal to the current signal terminal, that is, toward the current setting signal source.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS. First, Fig. 1
FIG. 3 is a diagram showing an electrical configuration of an analog setting signal input circuit of the motor control device. In FIG. 1, a voltage signal terminal 11 is a terminal for inputting a voltage setting signal of an analog setting signal (for example, a speed setting signal or the like) given from the outside, and a current signal terminal 12 is a terminal of the analog setting signal. Is a terminal for inputting the current setting signal. Then, between the voltage signal terminal 11 and the common terminal 13, for example, two voltage dividing resistors 14 and 15 are connected in series as resistors for voltage detection.

Further, the current signal terminal 12 and the common terminal 13
A current detection resistor 16 is connected between the and. Furthermore, between the current signal terminal 12 and the voltage signal terminal 11,
The first diode 17 is connected with the polarity shown in the drawing, and the voltage signal terminal 11 is connected by this first diode 17.
Is configured to block the current flowing from to the current detection resistor 16.

A capacitor 19 constituting a noise reduction filter 18 is connected between the terminals of the voltage dividing resistor 15 on the common terminal 13 side, and an input terminal of an A / D converter 20 is connected. Has been done. The A / D converter 20 has a function of inputting a voltage between terminals of the voltage dividing resistor 15 and A / D converting the input voltage. This A / D
The converted digital signal is transmitted to the motor controller 21 (see FIG. 2).
Other device incorporated in the CPU 22 (see FIG. 2).
See)).

Now, the analog setting signal input circuit 23 configured as described above is provided in the motor controller 21 as shown in FIG.
It is built in as shown in. The motor control device 21
Has a function of controlling energization of a motor such as an induction motor, and stores a control program therefor in a built-in memory (ROM, RAM, etc.). The motor control device 21 is a main controller, for example, the programmable controller 2 via the transmission cable 24.
5 to transmit and receive data. As the main controller, a personal computer, a minicomputer, or the like may be used instead of the programmable controller 25. In addition, the transmission cable 24 includes two transmission lines 24.
It is composed of a and 24b.

In the case of the above configuration, the motor controller 21 receives the received data (programmable controller 25
Data transmitted from the transmission line 24 through the transmission device 26 and transmission data (data to be transmitted to the programmable controller 25) transmitted from the transmission device 2
6 for transmission to the transmission line 24. This transmission device 26 is an interface standard for data communication (transmission), for example, RS232C, RS4.
This is a device for matching data with the standards such as 22, RS485, etc., and is mainly composed of a buffer as shown in FIG.

The transmission device 26 and the motor control device 21 are connected by a connection cable 27. The connection cable 27 is composed of five connection lines 27a to 27e. Specifically, the connection line 27a that connects the data output terminal SOT of the CPU 22 of the motor control device 21 and the input terminal 26a of the transmission device 26, and the CPU 22
Data input terminal SIN and output terminal 26 of the transmission device 26
b, a connection line 27b connecting the transmission / reception switching signal output terminal EN of the CPU 22 and the input terminal 26c of the transmission device 26, a power supply terminal (+, −) of the motor control device 21 and the transmission device. It is composed of two connection lines 27d and 27e that connect the power supply terminals (+, −) of 26.

In the case of this embodiment, the motor control device 21 is housed in the case for one control device, and the transmission device 26 is for the transmission device separate from the case for the control device. It is housed in a case. Furthermore, plugs are provided at both ends of the connection cable 27 (connection wires 27a to 27e), and a jack into which one plug of the connection cable 27 is inserted and connected is provided in the case of the motor control device 21. The case of the device 26 is provided with a jack into which the other plug of the connection cable 27 is inserted and connected.

In addition to the above-described motor control device 21, the transmission cable 24 includes, for example, three motor control devices 2
8, 29 and 30 are connected via transmission devices 31, 32 and 33, respectively. These motor control devices 28, 2
9, 30 and the transmission devices 31, 32, 33 have the same configurations as the motor control device 21 and the transmission device 26 described above.
The motor control devices 28, 29, 30 are connected to the transmission devices 31, 32, 33 via connection cables 34, 35, 36.

Therefore, in this embodiment, the programmable controller 25 includes four motor control devices 21, 28-.
30 is configured to be controlled separately. In this case, the programmable controller 25 controls the four motor control devices 21, 28 to 30 by, for example, time division control, and the data transmitted to each motor control device is provided with an identification code for identifying each motor control device. I am trying.

Next, the operation of the above-described structure, particularly the operation of the analog setting signal input circuit 23 will be described. First, when inputting an analog voltage setting signal, in FIG.
The voltage setting signal is input to the voltage signal terminal 11. Then, the voltage setting signal is divided by the voltage dividing resistors 14 and 15 and falls within the input voltage range of the A / D converter 20. Subsequently, the voltage-divided signal (voltage between the terminals of the voltage-dividing resistor 15) is filtered by the filter 18 to remove noise, and then input to the A / D converter 20 and A / D-converted. The A / D-converted digital signal is applied to the CPU 22 of the motor control circuit 21.

Here, even if the voltage setting signal tries to flow from the voltage signal terminal 11 toward the current detecting resistor 16, it is blocked by the first diode 17. Thereby, even if the voltage setting signal source is connected to the current signal terminal 12, the voltage setting signal source can be prevented from being damaged.

When an analog current setting signal is input, the current setting signal is input to the current signal terminal 12. Then, the current setting signal flows through the current detecting resistor 16 and a voltage is generated between the terminals of the current detecting resistor 16. Subsequently, the generated voltage is divided by the voltage dividing resistors 14 and 15 and then passed through the filter 18 before being input to the A / D converter 20 and A / D converted. There is. In this case, the resistance values of the voltage dividing resistors 14 and 15 are set to a value considerably larger than that of the current detecting resistor 16, and the current input impedance is configured to be substantially equal to the resistance value of the current detecting resistor 16. Has been done. Therefore,
Even if the current setting signal flows to the voltage dividing resistors 14 and 15 (voltage detecting resistors), the current does not flow too much because the resistance values of the voltage dividing resistors 14 and 15 are large. Further, since the current from the current setting signal source is a constant current, too much current does not flow and the current setting signal source is not damaged.

In the present embodiment having the above-described structure, unlike the conventional structure (see FIG. 9), the jumper pin 5 for input switching becomes unnecessary and the input switching work becomes unnecessary. For this reason, in the above-described embodiment, the reliability of the motor control device 21 is increased because the number of mechanical contacts is reduced, and the short-circuit component of the jumper pin 5 is replaced by the motor control device 2.
Since it does not drop into the first case, there is no possibility that the electric circuit arranged in the case is short-circuited or damaged. Further, in the above-described embodiment, since the input switching work is unnecessary, erroneous switching is eliminated, a relatively large current does not flow into the A / D converter 20 and the like, and the A / D converter 20 and the like are damaged. Can be reliably prevented.

By the way, as shown in FIG. 10, a motor control device 51 having a conventional structure has a built-in transmission device 52.
In this case, the transmission device 52 is also mounted on the printed wiring board on which the motor control device 51 is mounted. For this reason, in the above-described conventional configuration, it is necessary to manufacture the motor control device 51 in which the transmission devices 52 corresponding to a plurality of interface standards for data communication (transmission) are mounted.

Also, a structure in which the printed wiring board on which the motor control device 51 is mounted and the printed wiring board on which the transmission device 52 is mounted are separately manufactured. However, in the case of this configuration, since the two printed wiring boards are accommodated in one case, even if the motor control device 51 side fails, for example, the motor control device 51 and The transmitter 52 must be removed. For this reason, it is necessary to remove the transmission cable, and there is a problem that the transmission cable must be cut off, that is, the driving of the other motor control device and the programmable controller 25 must be stopped.

On the other hand, in the above embodiment, the motor control device 21 and the transmission device 26 are housed in separate cases, and the both devices 21 and 26 are connected by the connection cable 27.
(Connecting wires 27a to 27e) are used to connect by a so-called plug jack method. Therefore, in the above-described embodiment, only the transmission device 26 corresponding to each of a plurality of interface standards needs to be manufactured, and the motor control device 21 can use one in common even if the interface standards are different. . Further, in the above embodiment, when the motor control device 21 side is out of order, only the printed wiring board of the motor control device 21 can be taken out from the case on the motor control device 21 side for repair. Moreover, in this case, since the motor control device 21 can be repaired by removing the connection cable 27 connecting the motor control device 21 and the transmission device 26, the work of removing the transmission cable 24 becomes unnecessary, and the transmission cable 24 can be replaced. In the state in which the motor is operating, that is, the other motor control device 2
8 to 29 and the programmable controller 25 can be repaired while operating, and the maintenance work is easy and simple.

In the above embodiment, the voltage detecting resistor is set to 2
Although it is configured by the voltage dividing resistors 14 and 15, when it is not necessary to divide the voltage setting signal (that is, the voltage setting signal is A
If it falls within the input voltage range of the / D converter 20, the voltage detecting resistor may be configured by one resistor.

FIG. 3 shows a second embodiment of the present invention, and the difference from the first embodiment will be described. The same parts as those in the first embodiment are designated by the same reference numerals. In the second embodiment, as shown in FIG. 3, the current signal terminal 1
A second diode 37 that allows a current to flow from the current signal terminal 12 toward the current detection resistor 16 is connected between the 2 and the current detection resistor 16. The configuration of the second embodiment other than this configuration is the same as the configuration of the first embodiment.

Therefore, also in the second embodiment, the same operational effect as in the first embodiment can be obtained. In particular,
According to the second embodiment, the second diode 37 can cancel or reduce the forward voltage drop and the temperature drift of the first diode 17.

FIG. 4 shows a third embodiment of the present invention, and the difference from the second embodiment will be described. The same parts as those in the second embodiment are designated by the same reference numerals. In the third embodiment, the first diode 17 and the second diode 37 in the second embodiment are configured by one transistor, for example, an NPN type transistor. Specifically, as shown in FIG. 4, the base of the NPN transistor 38 is connected to the current signal terminal 12, the emitter is connected to the terminal of the current detection resistor 16 on the side of the current signal terminal 12, and the collector is connected. Is connected to the voltage signal terminal 11. The configuration of the third embodiment other than the above is the same as the configuration of the second embodiment. Therefore, even in the third embodiment, the second
It is possible to obtain the same effect as that of the embodiment.

In the third embodiment, the emitter of the NPN transistor 38 is connected to the current signal terminal 12 side terminal of the current detecting resistor 16, and the collector is connected to the voltage signal terminal 11. Instead of this, as in the fourth embodiment shown in FIG. 5, the collector of the NPN transistor 38 is connected to the current signal terminal 1 of the current detecting resistor 16.
It may be configured such that it is connected to the terminal on the second side and the emitter is connected to the voltage signal terminal 11. Also in the case of the fourth embodiment, the same operational effect as that of the third embodiment can be obtained.

FIG. 6 shows a fifth embodiment of the present invention, and the difference from the first embodiment will be described. The same parts as those in the first embodiment are designated by the same reference numerals. In the fifth embodiment, as shown in FIG. 6, the voltage signal terminal 1
Between the 1 and the common terminal 13, for example, three voltage dividing resistors 39, 40, 41 are connected in series as a plurality of voltage detecting resistors. Then, these three voltage dividing resistors 39, 4
The resistance on the common terminal 13 side of 0 and 41, in this case,
The voltage between both terminals of the combined resistance in which the voltage dividing resistor 40 and the voltage dividing resistor 41 are connected in series is input to the A / D converter 20. Further, the current signal terminal 12 is connected to an intermediate connection point of the three voltage dividing resistors 39, 40, 41, specifically, an intermediate connection point of the voltage dividing resistor 40 and the voltage dividing resistor 41.

In this configuration, when the voltage setting signal is input to the voltage signal terminal 11, the voltage setting signal is applied to the voltage dividing resistor 3
It is divided by 9, 40 and 41. In this case, the inter-terminal voltage of the combined resistance in which the voltage dividing resistor 40 and the voltage dividing resistor 41 are connected in series falls within the input voltage range of the A / D converter 20. Then, the voltage between the terminals is applied to the filter 18
After the noise is removed by passing through, the signal is input to the A / D converter 20 and A / D converted.

On the other hand, when the current setting signal is input to the current signal terminal 12, the current setting signal flows through the voltage dividing resistor 41 and a voltage is generated between the terminals of the voltage dividing resistor 41. Subsequently, the generated voltage passes through the voltage dividing resistor 40 and further through the filter 18, and then is input to the A / D converter 20 to be A / D converted.
It is configured to be converted. In this case, the resistance value of the voltage dividing resistor 40 is set to a value considerably larger than that of the voltage dividing resistor 41, so that almost no current flows to the A / D converter 20. Therefore, the voltage drop due to the voltage dividing resistor 40 is almost negligible.

The configuration of the fifth embodiment other than the above is the same as that of the first embodiment. Therefore, also in the fifth embodiment, it is possible to obtain the same effect as that of the first embodiment.

FIG. 7 shows a sixth embodiment of the present invention, and the difference from the fifth embodiment will be described. The same parts as those in the fifth embodiment are designated by the same reference numerals. In the sixth embodiment, as shown in FIG. 7, the current signal terminal 1
A second diode 42 for blocking a current flowing from the voltage signal terminal 11 to the current signal terminal 12 is connected between the voltage dividing terminal 2 and the intermediate connection point of the voltage dividing resistor 40 and the voltage dividing resistor 41. ing. The configuration of the sixth embodiment other than the above is the same as the configuration of the fifth embodiment.

Therefore, also in the sixth embodiment, it is possible to obtain the same effect as that of the fifth embodiment. In particular, the sixth
In this embodiment, the third diode 42 can surely prevent the current from flowing from the voltage signal terminal 11 to the current signal terminal 12, that is, toward the current setting signal source.

FIG. 8 shows a seventh embodiment of the present invention, and the difference from the first embodiment will be described. The same parts as those in the first embodiment are designated by the same reference numerals. In the seventh embodiment, as shown in FIG. 8, three motor control devices 21, 43 and 44 having the same configuration are used as one transmission device 4.
5 is connected to the transmission cable 24. Specifically, the transmission device 45 connects the three motor control devices 21, 43 and 44 to the connection cables 27, 46 and 47.
Terminals 48a to 48e and 49a for connection via
It has 49e and 50a-50e.

In this case, five terminals of the motor control device 21 (data output terminal SOT, data input terminal SIN, transmission / reception switching signal output terminal EN, power supply terminal (+ ,-)) And the terminals 48a to 48e of the transmission device 45 are connected to each other, and the five connection lines 46a to 46e of the connection cable 46 connect the five terminals of the motor control device 43 (data output terminal SOT, data input terminal SIN, The transmission / reception switching signal output terminal EN and the power supply terminals (+,-) are connected to the terminals 49a to 49e of the transmission device 45, and the five connection wires 47a to 47 of the connection cable 47 are connected.
The five terminals (data output terminal SOT, data input terminal SIN, transmission / reception switching signal output terminal EN, power supply terminals (+,-)) of the motor control device 44 and the terminals 50a to 50e of the transmission device 45 are connected by e. There is.

Then, a terminal 48 is provided in the transmission device 45.
An AND circuit 51 for ANDing the three data signals input from a, 49a, and 50a is provided, and
An AND circuit 52 is provided for ANDing the three transmission / reception switching signals input from the terminals 48c, 49c, 50c. The output terminal of the AND circuit 51 is connected to the input terminal 26a of the transmission buffer.
The second output terminal is connected to the respective operation switching terminals 26c of the transmission buffer and the reception buffer. Further, the output terminal 26b of the receiving buffer is the terminals 48b and 49b.
b, 50b.

In the case of the above configuration, three motor control devices 2
The transmission / reception switching signals output from 1, 43, and 44 are said to be in a receiving state when they are at a high level, and are in a transmitting state when they are at a low level. As a result, when a low-level transmission / reception switching signal is output from one of the three motor control devices 21, 43, 44, the AND circuit 52 causes the transmission device 45 to switch to the transmission state. Then, the three motor control devices 21, 43, 44
The high level of the transmission signal output from is in the normal state, and the low level is in the state of outputting the signal. As a result, the three motor control devices 21, 4 are switched while the transmission device 45 is switched to the transmission state.
When a transmission signal is output from one of the cables 3 and 44, the transmission signal passes through the AND circuit 51 and the transmission cable 24.
It is configured to be output to.

When the transmission device 45 is switched to the reception state, the three motor control devices 21, 43, 44 are used.
Are configured to be able to receive data at the same time.
Since the programmable controller 25 controls each motor control device 21, 43, 44 by time-division control, the above-mentioned one transmission device 45 is used to
Base motor control devices 21, 43, 44 and transmission cable 2
It is possible to execute transmission / reception of data to / from the mobile terminal 4. The configuration of the seventh embodiment other than the above is the same as that of the first embodiment.

Therefore, also in the seventh embodiment, it is possible to obtain the same effect as that of the first embodiment. In particular, the 7th
In this embodiment, three motor control devices 21, 43, 44 are used.
Is configured to be connected to the transmission cable 24 via one transmission device 45, the number of installed transmission devices can be reduced, and the overall configuration can be downsized and simplified.

[0046]

As is apparent from the above description, the present invention is provided with a voltage signal terminal for inputting an analog voltage setting signal and a current signal terminal for inputting an analog current setting signal. Connect a voltage detection resistor between the common terminal, a current detection resistor between the current signal terminal and the common terminal, and connect a current from the voltage signal terminal between the current signal terminal and the voltage signal terminal. Since the first diode that blocks the current flowing toward the input resistor is connected, and the voltage between the terminals of the voltage detection resistor is A / D converted by the A / D converter, the input switching The jumper pin is not needed, and the reliability of the device can be improved. Moreover, since the input switching work is unnecessary, the device damage that occurs at the time of switching can be prevented and erroneous switching can be prevented. It was an effect.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram of an analog setting signal input circuit showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration in which a motor control device, a transmission device, and a programmable controller are connected to a transmission cable.

FIG. 3 is a diagram corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 4 is a diagram corresponding to FIG. 1 showing a third embodiment of the present invention.

FIG. 5 is a view corresponding to FIG. 1 showing a fourth embodiment of the present invention.

FIG. 6 is a view corresponding to FIG. 1 showing a fifth embodiment of the present invention.

FIG. 7 is a diagram corresponding to FIG. 1 showing a sixth embodiment of the present invention.

FIG. 8 is a diagram corresponding to FIG. 2 showing a seventh embodiment of the present invention.

9 is a view corresponding to FIG. 1 showing a conventional configuration.

FIG. 10 is a view corresponding to FIG.

[Explanation of symbols]

11 is a voltage signal terminal, 12 is a current signal terminal, 13 is a common terminal, 14 is a voltage dividing resistor (voltage detecting resistor), 15 is a voltage dividing resistor (voltage detecting resistor), 16 is a current detecting resistor, 1
7 is a first diode, 18 is a filter, 20 is an A / D
Converter, 21 is a motor control device, 23 is an analog setting signal input circuit, 24 is a transmission cable, 25 is a programmable controller, 26 is a transmission device, 27 is a connection cable, 28, 29, 30 are motor control devices, 31, 32 ,
33 is a transmission device, 34, 35 and 36 are connection cables, 3
7 is a second diode, 38 is a transistor, 39, 4
0 and 41 are voltage dividing resistors (voltage detecting resistors), 42 is a third diode, 43 and 44 are motor control devices, 45 is a transmission device, 46 and 47 are transmission cables, 48, 49 and 50 are connection cables, Reference numerals 51 and 52 denote AND circuits.

Claims (5)

(57) [Claims] 1. A voltage signal terminal for inputting an analog voltage setting signal, a current signal terminal for inputting an analog current setting signal, and a voltage detection resistor connected between the voltage signal terminal and a common terminal. A current detection resistor connected between the current signal terminal and the common terminal; and a current detection resistor connected between the current signal terminal and the voltage signal terminal, from the voltage signal terminal to the current detection resistor An analog setting signal input circuit of a motor control device, comprising: a first diode that blocks a current that flows as a result and an A / D converter that inputs the voltage across the voltage detection resistor and performs A / D conversion. 2. A second diode connected between the current signal terminal and the current detection resistor, the second diode allowing a current flowing from the current signal terminal toward the current detection resistor. The analog setting signal input circuit of the motor control device according to claim 1. 3. The analog setting signal input circuit for a motor control device according to claim 2, wherein the first diode and the second diode are configured by one transistor. 4. A voltage signal terminal for inputting an analog voltage setting signal, a current signal terminal for inputting an analog current setting signal, and a plurality of voltages connected in series between the voltage signal terminal and a common terminal. A plurality of detection resistors and an A / D converter for A / D converting by inputting an inter-terminal voltage of the resistors on the common terminal side among the plurality of voltage detection resistors, An analog setting signal input circuit for a motor control device, characterized in that it is connected to an intermediate connection point of the voltage detection resistor of. 5. A third diode connected between the current signal terminal and an intermediate connection point of the plurality of voltage detection resistors, the third diode blocking a current flowing from the voltage signal terminal to the current signal terminal. The analog setting signal input circuit of the motor control device according to claim 4, further comprising: