JP2013183265A - No-voltage contact reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of reliably reading whether a no-voltage contact output is on or off which minimizes power consumption.SOLUTION: The no-voltage contact reading device outputs a voltage to a no-voltage contact output device via a power supply line by means of an arbitrary voltage output function provided in the no-voltage contact reading device, and measures a voltage by means of a voltage monitoring function provided in the no-voltage contact reading device. A contact state of the no-voltage contact output device is determined on the basis of the measured voltage, and the voltage of the arbitrary voltage output function is determined accordingly.

Description

  The present invention relates to a no-voltage contact reading device that can read open / close of a no-voltage contact of a no-voltage contact output unit.

  Conventionally, there are many industrial devices (equipment) with no-voltage contact output. The non-voltage contact is supplied with voltage and current from the outside, and the contact open / close can be known externally. For industrial use, the electrical specifications for supplying power to the non-voltage contact are mostly 5 to 24 V, which are often used in industrial use. In the no-voltage contact output, the operating status of the apparatus, information measured by the apparatus, and the like are output. On the other hand, there is an increasing demand to connect information on non-voltage contacts of existing industrial devices to a communication device.

  Several methods can be considered for communication of existing industrial devices, but the simple method is to use a non-voltage contact reader having a wireless function. This is because wireless communication eliminates the need for communication lines and simplifies installation work. However, even in this case, a power source for the non-voltage contact reading device itself is necessary, but there may be a case where a sufficient power source cannot be secured depending on the installation location of the industrial device. If the non-voltage contact reader can be driven by a battery, it will be possible to communicate and wirelessly install industrial equipment installed in every place, and installation work will be simplified.

Japanese Patent Laid-Open No. 1-220274

  However, as described above, the non-voltage contact output of industrial equipment needs to be supplied with a voltage that is easy to prepare for industrial use, but it is not considered to supply power with a battery. There is a problem that the power is too large. In general, it is necessary to supply a higher voltage than the battery voltage. In the conventional method, even when the no-voltage contact output is closed, a large amount of current is consumed because the current from the external power supply continues to flow.

  Patent Document 1 can be cited as a solution to this problem. Patent Document 1 discloses that a non-voltage contact is changed from open to closed, and an outflow current until the non-voltage contact is opened only flows intermittently, so that the power consumption is reduced, the apparatus is downsized and the cost is low. It is a plan to make it.

  However, non-voltage contacts include mechanical contacts that do not know whether or not the contacts are closed unless a certain voltage or more is applied to destroy the oxide film on the contact surface, and those that can be opened and closed with a small voltage. Therefore, it is difficult to suppress power consumption unless energization is performed under conditions according to the type of contact, and sufficient battery driving time cannot be ensured.

  In view of the above-mentioned drawbacks of the prior art, the present invention provides a contact reading device that energizes under optimum conditions with less power consumption depending on the type of contact.

In order to solve the above problems, the present invention provides a voltage output unit that supplies power to an external non-voltage contact via a current limiting resistor, and a voltage that measures the voltage of the current limiting resistor by power supply from the voltage output unit. In a no-voltage contact reading device that includes a monitoring unit and detects the open / closed state of an external no-voltage contact based on the measured voltage,
The voltage output unit is configured to output an arbitrary voltage, and based on the voltage measured by the voltage monitoring unit, a control for determining the energization state of the non-voltage contact and determining the power supply voltage of the voltage output unit And a non-voltage contact is fed from the voltage output unit with the determined voltage.

  Further, in the above-described no-voltage contact reading device, the control unit determines the type of the no-voltage contact from the energized state of the no-voltage contact and determines the supply voltage according to the type.

  In the above-described no-voltage contact reading device, the control unit may determine whether the no-voltage contact is a mechanical type or a semiconductor type from the energized state of the no-voltage contact.

  In the non-voltage contact reading device described above, when the external non-voltage contact is a mechanical contact, the control unit controls to supply a high voltage from the voltage output unit.

  In the non-voltage contact reading device described above, when the external non-voltage contact is a semiconductor contact, the control unit controls to supply a low voltage from the voltage output unit.

  In the above-described no-voltage contact reading device, when the external no-voltage contact is a C-contact, the control unit includes a current limiting resistor and a voltage output unit for supplying power to the A-contact and the B-contact of the no-voltage contact, respectively. Is configured to control the voltage output unit to stop the power supply to the non-voltage contact when a contradiction is detected in the opening and closing of the A contact and the B contact from the energized state based on the voltage measured by the voltage monitoring unit. And

  In the above-described no-voltage contact reading device, when the external no-voltage contact is a C-contact, the control unit includes a current limiting resistor and a voltage output unit for supplying power to the A-contact and the B-contact of the no-voltage contact, respectively. Is characterized in that the voltage output unit is controlled to supply power to an open contact of the A contact and the B contact from an energized state based on the voltage measured by the voltage monitoring unit.

  According to the present invention, the power consumption of the no-voltage contact reading device is minimized, and the battery can be driven.

It is a block diagram of the no-voltage contact reader of Example 1 of the present invention. It is a block diagram of the no-voltage contact reader of Example 2 of this invention. It is an operation | movement flowchart of this invention Example 1. FIG. It is an operation | movement flowchart of this invention Example 2. FIG.

  FIG. 1 is a configuration diagram of a no-voltage contact reading device according to Embodiment 1 of the present invention. Reference numeral 1 denotes a no-voltage contact output unit provided in the industrial device 8, and the built-in no-voltage contact 1 a is opened and closed as the industrial device 8 operates.

  Reference numeral 2 denotes a no-voltage contact reader, which measures the voltage of the current-limiting resistor 4 that is fed from the voltage output unit 3 and the voltage output unit 3 that feeds the external no-voltage contact 1a via the current-limiting resistor 4 And a control unit 6 for controlling each of the above-described units, and the opening and closing of an external no-voltage contact is detected.

  The voltage output unit 3 includes a battery and an electronic circuit that outputs an arbitrary voltage so as to increase or decrease the voltage according to a command from the control unit 6. Based on the power supply from the voltage output unit 3 to the non-voltage contact 1a, the voltage monitoring unit 5 measures the voltage of the current limiting resistor 4, and based on the measured voltage, the control unit 6 supplies the non-voltage contact 1a. Determine the state. Furthermore, the control unit 6 determines the supply voltage of the voltage output unit 3 based on the energized state, and supplies power from the voltage output unit 3 to the non-voltage contact with the determined voltage.

  When the no-voltage contact 1a is closed, the energizing current flows into the ground 7 regardless of the voltage output from the voltage output unit 3, so that the voltage of the current limiting resistor 4 becomes the same as the potential of the ground 7 and voltage monitoring Unit 5 measures a voltage of 0V. On the other hand, when the non-voltage contact 1a is open, no energization current flows, so the voltage of the current limiting resistor 4 becomes the same as the output voltage of the voltage output unit 3, and the voltage monitoring unit 5 measures this output voltage. Thus, the open / closed state of the non-voltage contact can be detected based on the voltage measured based on the energized state. The detected opening / closing detection result is output to an external receiver by radio in accordance with a command from the control unit 6.

  In the first embodiment, the output voltage of the voltage output unit 3 is gradually increased. The power supply voltage monitoring function 5 always measures 0V when the contact 1a of the no-voltage contact output unit 1 is closed. In this case, the voltage output unit 3 performs voltage output with the highest power efficiency. The voltage having the best power efficiency is a value determined when the circuit of the voltage output unit 3 is designed. Depending on the contact information of the non-voltage contact output unit 1, there is a case where it is not always necessary to monitor the contact, for example, when the closing time is long. In this case, the voltage output itself of the voltage output unit 3 is stopped. There is also. In this case, after the output voltage of the voltage output unit 3 is stopped for a certain period of time, the output voltage is gradually increased and the voltage monitoring unit 5 repeatedly measures the voltage.

  When the voltage of the voltage output unit 3 is gradually increased, the voltage monitoring unit 5 determines that the contact 1a of the non-voltage contact output unit 1 is open when monitoring the voltage gradually increasing in proportion thereto. it can. At this time, the output current of the voltage output unit 3 is the sum of the current flowing through the voltage monitoring unit 5 and the leakage current of the contact 1a of the no-voltage contact output unit 1. When the contact 1a of the no-voltage contact output unit 1 is a mechanical contact, the leakage current is almost equal to 0, but when it is a semiconductor contact, the amount of current is not negligible. When the leakage current is large compared to the case where the leakage current is small, the current flowing through the current limiting resistor 4 is also increased, so that the voltage of the current limiting resistor 4 measured by the voltage monitoring unit 5 is lowered. As described above, the control unit 6 can determine the type of the contact whether the contact 1a of the no-voltage contact output unit 1 is a mechanical type or a semiconductor type from the energized state of the no-voltage contact.

  The type of the contact 1a of the no-voltage contact output unit 1 is considered to be determined automatically by the no-voltage contact reader 2 as described above, or otherwise set in advance in the no-voltage contact reader 2. . In either case, it is necessary to change the output voltage of the voltage output unit 3 according to the type of the contact 1a of the no-voltage contact output unit 1. That is, in the case of a semiconductor contact, since the closing / opening of the contact can be read even with a relatively low voltage, the output voltage of the voltage output unit 3 is lowered to reduce power consumption. In the case of a mechanical contact, the deterioration of the contact (an oxide film is formed on the contact surface due to aging and the contact resistance increases) may be eliminated by applying a high voltage (removing the oxide film) Outputs high voltage. Even when a high voltage is applied, in the case of a mechanical contact, since the leakage current when the contact is open is equal to 0, power consumption does not increase and high voltage efficiency can be realized. As described above, the power consumption of the no-voltage contact reading device can be minimized.

  Next, the above operation will be described with reference to the flowchart of FIG. In steps (S) 100 and 101, a voltage is output from the voltage output unit 3 to the non-voltage contact 1a, and the voltage is gradually increased. The control unit 6 determines the energization state from the change in the voltage of the current limiting resistor 4 measured by the voltage monitoring unit 5 in S102. That is, in S102, it is determined whether the measured voltage increases in proportion to the output voltage. When the measured voltage increases in proportion (Y), it is determined that the contact is open, and when the measured voltage does not increase in proportion (N), the contact is closed. Is determined.

  When the contact is open (Y) in S102, the presence or absence of leakage current is checked in the next S103. When the leakage current is present (Y), the contact 1a is determined as a semiconductor contact in S104, and when there is no leakage (N), the contact 1a is determined as a mechanical contact in S107. Next, the control unit 6 determines the power supply voltage to a low value (for example, 0.7 V which is the ON voltage of silicon) at S105 when the semiconductor contact is used, and controls the voltage output unit 3 to output this low voltage. . Further, the control unit 6 determines the power supply voltage to a high value (voltage that can destroy the oxide film) in S108 at the time of the mechanical contact, and controls the voltage output unit 3 to output this high voltage. As described above, the presence or absence of leakage current is determined by the fact that when there is leakage current, the current flowing through the current limiting resistor 4 also increases and the voltage measured by the voltage monitoring unit 5 decreases.

  On the other hand, after it is determined in S102 that the measured voltage does not increase in proportion to the output voltage (N) and the contact is closed, it is determined in S106 whether the measured voltage is slightly increased. When the measured voltage is slightly increased (Y), it is determined in S104 that the contact 1a is a semiconductor contact. A slight increase means that the semiconductor contact is increased by an ON voltage (0.7 V in the case of silicon) when the semiconductor contact is closed (conducted). When the measured voltage does not increase slightly in S106 (N), it is determined in S107 that the contact 1a is a mechanical contact. In subsequent S105 and S108, the power supply voltage corresponding to the type of contact is determined, and the voltage output unit 3 is controlled so that each voltage is output.

  Next, Example 2 in the case where the no-voltage contact is a C contact will be described. As shown in FIG. 2, the no-voltage contact output unit 21 includes a no-voltage C contact provided with an A contact and a B contact. The no-voltage contact output unit 21 is provided in the industrial device 8, and the built-in no-voltage contact 21 a is selectively switched between the A contact and the B contact with the operation of the industrial device 8.

  Reference numeral 22 denotes a non-voltage contact reading device, a voltage output unit A23 that supplies power to the A contact through a current limiting resistor A24, and a voltage monitoring unit that measures the voltage of the current limiting resistor A24 by power supply from the voltage output unit 23. A25 and a control unit 29 for controlling each of the above parts are provided, and the opening and closing of the A contact of the external no-voltage contact is detected.

  Further, the no-voltage contact reader 22 includes a voltage output unit B26 that supplies power to the B contact via a current limiting resistor B27, and a voltage that measures the voltage of the current limiting resistor B27 that is supplied by the voltage output unit B26. A monitoring unit B28 is provided, and the control unit 29 detects the opening and closing of the B contact of the external no-voltage contact.

  The voltage output units 23 and 26 are constituted by a battery and an electronic circuit that outputs an arbitrary voltage by controlling the voltage according to a command from the control unit 29.

  The determination of the state of the energization current of the contact of the non-voltage contact output unit 21 is performed by using that the B contact is open when the A contact is closed and the B contact is closed when the A contact is open. It is possible to reduce the power and diagnose the contact itself.

  In this case, a voltage is output from the voltage output unit to the contact open side, and no voltage is output to the closed contact. When the voltage monitoring unit detects that the contact is closed, the control unit 29 switches the contact that outputs the voltage from the closed contact to the open contact. Since the power consumption of the voltage output unit increases when the contact is closed, it is possible to determine whether the contact is closed or open by continuously monitoring only the contact that consumes less power, which helps to reduce power consumption. When the contact to be monitored is closed, the other open contact is monitored. If the other contact is monitored but the other contact is closed, it is determined that the contact has failed. it can. Alternatively, even if the monitored contact is open, the contacts that should be closed at appropriate intervals are monitored. At this time, if the contact that should be closed is open, it can be determined that the contact has failed. As described above, in the second embodiment, since the contact failure diagnosis can be performed at the same time while reducing the power consumption, the reliability of the contact output can be improved.

  Next, the above operation will be described with reference to the flowchart of FIG. First, a voltage is output from the power output unit A23 to the A contact in S200, and it is determined whether or not the A contact is closed in S201. This determination is performed in the same steps as S101 and S102 of FIG.

  When the A contact is closed in S201 (Y), a voltage is output from the power output unit B26 to the B contact. Next, in S203, it is determined whether or not the B contact is open. If the B contact is closed (N), there is a contradiction in the opening and closing of the A contact and the B contact, and the supply of voltage to both contacts is stopped as a contact failure. The determination in S203 is performed for the B contact in the same steps as S101 and S102 in FIG.

  If the B contact is open in S203 (Y), the voltage output to the A contact is stopped and the voltage output to the B contact is continued in S205. In step S206, the voltage at the B contact is monitored by the voltage monitoring unit B28.

  On the other hand, if the A contact is open in S201 (N), it is determined in S207 whether the B contact is closed. If the B contact is closed (Y), a voltage is output to the A contact, and it is determined in the next S209 whether the A contact is open. Here, if the A contact is closed, (N) there is a contradiction in the opening and closing of the A contact and the B contact, and the supply of voltage to both the contacts is stopped as a contact failure.

  If the A contact is open in S209 (Y), the voltage output to the B contact is stopped and the voltage output to the A contact is continued in the next S211. In step S212, the voltage at the A contact is monitored by the voltage monitoring unit A25. This monitoring continues to S201.

  After monitoring the voltage at the B contact in S206, the process goes to S207. If the B contact is open in S207 (N), the process goes to S206.

  Thus, according to the second embodiment, the determination of the state of the energization current of the contact is made using the fact that the B contact is open when the A contact is closed and the B contact is closed when the A contact is open. The power consumption can be reduced by outputting the voltage from the voltage output unit to the contact open side and not outputting the voltage to the closed contact. In addition, when a contradiction is detected in the opening and closing of the A contact and the B contact from the energized state based on the voltage measured by the voltage monitoring unit, power supply to the non-voltage contact is stopped as a failure of the contact itself. Reduction and diagnosis are possible.

  1, 21 ... Non-voltage contact output unit, 1a, 21a ... Non-voltage contact, 2, 22 ... Non-voltage contact reader, 3, 23, 26 ... Voltage output unit, 4, 24, 27 ... Current limiting resistor, 5, 25, 28 ... Voltage monitoring unit, 6, 29 ... Control unit, 7 ... Earth, 8 ... Industrial device, 23 ... Voltage output unit A, 26 ... Voltage output unit B, 24 ... Current limiting resistor A, 27 ... Current limiting resistor B, 25 ... Voltage monitoring part A, 28 ... Voltage monitoring part B, A ... A contact, B ... B contact.

Claims (7)

A voltage output unit that supplies power to an external non-voltage contact via a current limiting resistor and a voltage monitoring unit that measures the voltage of the current limiting resistor by power supply from the voltage output unit are provided. In the no-voltage contact reader that detects the open / close state of the voltage contact,
The voltage output unit is configured to output an arbitrary voltage, and based on the voltage measured by the voltage monitoring unit, a control for determining the energization state of the non-voltage contact and determining the power supply voltage of the voltage output unit And a non-voltage contact reading device that feeds power from the voltage output unit to the non-voltage contact with the determined voltage.   2. The no-voltage contact reading device according to claim 1, wherein the control unit determines the type of the no-voltage contact from the energized state of the no-voltage contact and determines the supply voltage according to the type. Reader.   3. The no-voltage contact reading device according to claim 2, wherein the control unit determines whether the no-voltage contact is a mechanical type or a semiconductor type based on an energized state of the no-voltage contact.   4. The non-voltage contact reading device according to claim 3, wherein when the external non-voltage contact is a mechanical contact, the control unit controls to supply a high voltage from the voltage output unit. Voltage contact reading device.   4. The non-voltage contact reading device according to claim 3, wherein when the external non-voltage contact is a semiconductor contact, the control unit controls to supply a low voltage from the voltage output unit. Voltage contact reading device.   6. The non-voltage contact reading device according to claim 1, wherein when the external non-voltage contact is a C contact, a current limiting resistor and a voltage output unit for supplying power to the A contact and the B contact of the non-voltage contact, respectively. The controller outputs the voltage output unit so as to stop the power supply to the non-voltage contact when detecting a contradiction in the opening and closing of the A contact and the B contact from the energized state based on the voltage measured by the voltage monitoring unit. A non-voltage contact reading device characterized by controlling.   7. The non-voltage contact reading device according to claim 1, wherein when the external non-voltage contact is a C contact, a current limiting resistor and a voltage output unit for supplying power to the A contact and the B contact of the non-voltage contact, respectively. And the control unit controls the voltage output unit to supply power to an open contact of the A contact and the B contact from an energized state based on the voltage measured by the voltage monitoring unit. Contact reading device.

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