JP2014186709A - Temperature monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature monitoring system enabling information from a number of temperature sensors to be transmitted over a long distance, capable of accurately and rapidly detecting temperature change in each body to be measured without causing erroneous operation due to noise, and easily applicable to also an existing body to be measured.SOLUTION: A temperature monitoring system includes: a plurality of temperature sensors 1 for detecting temperature of a body 2 to be measured; a data collection device 5 connected to the temperature sensors 1 by cables 3; controllers 6, 7 for collecting and converting information from the data collection device 5; and a central monitor 8. The temperature sensors 1 and the data collection device 5 are connected together by the cables 3, a temperature sensor circuit used has a repeater circuit on the side of the data collection device 5, a signal is differentially transmitted through a twisted pair wire, and a pullup terminal resistance is provided at each of final ends of the sides of the plurality of temperature sensors 1.

Description

  The present invention relates to a temperature monitoring system, and more particularly to a temperature monitoring system used for temperature management in a wide range of fields such as a medical connection facility such as a hospital, a food factory, a server room, and a plastic house, including a conductor connection portion of a bus duct.

  A bus duct is a member for a trunk line that uses copper or aluminum as a conductor and the outside of the conductor is covered with a casing made of iron, aluminum, etc., and is used especially as a member for a power trunk line. It is used as the main trunk line on the secondary side of trunk lines and transformers. This bus duct has an advantage that the system can be converged as compared with a cable that is difficult to manage in the system arranged on the cable rack, the allowable current is large, and system management is easy.

  In this bus duct, the conductors are connected to each other by bolts, but even if the bolts are not tightened sufficiently or even if they are tightened sufficiently, the conductors are poorly connected for some reason due to use over time. Is worried about inviting. This results in poor conductor contact.

  Conventionally, visual inspection by an operator has generally been performed as means for inspecting the contact failure of the conductors of the bus duct. However, the inspection is complicated and lacks accuracy.

  For this reason, a temperature monitoring device that detects a contact failure of a conductor by providing a temperature sensor in the vicinity of the conductor connection portion has been used. The temperature monitoring device using this temperature sensor detects an abnormal temperature exceeding a predetermined value at a specific connection part. Specifically, a plurality of temperature sensors are arranged on the casing surface of the bus duct, and A plurality of temperature sensors and a central management room are connected by lead wires, respectively, and in the central monitoring room, a conductor connection failure and its location are detected by the occurrence of an abnormal temperature in the conductor connection part.

  However, in such a temperature monitoring device, it is necessary to individually connect a plurality of temperature sensors to the central monitoring room with lead wires, resulting in a complicated wiring structure and a great cost. Moreover, it is difficult to newly install such a temperature monitoring device in the existing bus duct.

  As a proposal for solving such a problem, Patent Document 1 (Japanese Patent Laid-Open No. 5-72080) discloses a temperature sensor at a position near a conductor connection portion of a bus duct casing and a reference value for setting a reference temperature at the position. An abnormal temperature detection unit comprising a setting unit, a comparison circuit that compares the output of the temperature sensor and the set value of the reference value setting unit, and a light emitting means that is driven by the output of the comparison circuit is installed, respectively. A temperature monitoring device for a bus duct has been proposed in which the detection output of the abnormal temperature detection unit is connected to an alarm device of a centralized monitoring unit through a common signal line.

  According to such a temperature monitoring device described in Patent Document 1, it is possible to detect the occurrence of an abnormal temperature rise in the connection portion in the central monitoring room, and after the detection, the patrol is performed along the bus duct line, and the abnormal temperature detection unit Because it is possible to identify the conductor connection part that caused an abnormal temperature rise due to the lighting or non-lighting of the alarm lamp, it is said that the maintenance and management of the bus duct line can be performed satisfactorily with a relatively low cost device. ing.

JP-A-5-72080

  However, when the temperature monitoring device described in Patent Document 1 is used, the temperature sensor that can be connected to one monitoring device is limited, and the measurement length is at most several tens of centimeters mail. For this reason, in a bus duct of several hundred meters, a large number of temperature monitoring devices are required to monitor a large number of conductor connection portions, and it is difficult to say that it is practical due to the complexity of equipment and the difficulty of construction.

  In such a temperature monitoring device, the temperature sensor is not provided in the bus duct casing but directly in the conductor connection portion of the bus duct. Furthermore, no consideration has been given to lead noise. For this reason, it is hard to say that the contact failure of the conductor connection portion of the bus duct can be accurately detected.

  FIG. 3 is a configuration diagram of a temperature sensor circuit used in a conventional temperature monitoring system. In FIG. 3, a single end system is used as the transmission method. Therefore, the communicable distance is about 30 m, and the communicable distance is extremely short. Further, the L and H determination levels of the input terminals of the node IC and the host IC used are as low as VIL = −0.3 to 0.8V, VIH = 2.2 to 5.5V, or 3 to 5.3V. Is. For this reason, the input level is likely to cause malfunction due to noise.

  For this reason, it is possible to transmit information from a large number of temperature sensors over a long distance, and malfunctions due to noise do not occur, and temperature changes caused by poor contact of conductor connection parts can be performed accurately and quickly. There was a need for a temperature monitoring system that could detect. There has also been a demand for a temperature monitoring system that can be easily applied to an existing object to be measured, for example, a conductor connection portion of a bus duct.

  Therefore, the object of the present invention is to enable transmission of information from a large number of temperature sensors over a long distance, and to detect a temperature change of each measured object accurately and quickly without causing malfunction due to noise. And it is providing the temperature monitoring system which can be easily applied also to the existing to-be-measured object.

  As a result of intensive studies, the present inventors have found that the temperature monitoring system shown below can solve the above problems, and have reached the present invention.

  That is, the present invention includes a plurality of temperature sensors that detect the temperature of the object to be measured, a data collection device connected to the temperature sensors with a cable, a controller that collects and converts information from the data collection device, A temperature monitoring system having a monitoring device, wherein the temperature sensor and the data collecting device are connected by a cable, and the temperature sensor circuit used has a repeater circuit on the data collecting device side, and the signal is a twisted pair. A temperature monitoring system is provided in which a differential transmission is performed by a line and a pull-up termination resistor is provided at a final end of the plurality of temperature sensors.

  In the temperature monitoring system according to the present invention, it is desirable that the cable is a shielded LAN cable and is connected to the plurality of temperature sensors by a T-branch.

  In the temperature monitoring system according to the present invention, it is desirable that the temperature sensor is directly installed on the measurement object by a detachable adhesive means.

  In the temperature monitoring system according to the present invention, the measured object is a conductor connection part of a bus duct.

  According to the temperature monitoring system of the present invention, information from a large number of temperature sensors can be transmitted over a long distance, and an abnormal temperature of each object to be measured can be accurately and quickly detected without causing malfunction due to noise. A temperature change such as occurrence can be detected. Further, since the temperature sensor of the temperature monitoring system according to the present invention is directly installed on the measured object by the detachable bonding means, it can be easily applied to the existing measured object. Furthermore, the temperature monitoring system according to the present invention is inexpensive because the system itself is simple.

  FIG. 1 is a schematic explanatory diagram of a temperature monitoring system according to the present invention.   FIG. 2 is a configuration diagram of a temperature sensor circuit used in the temperature monitoring system according to the present invention.   FIG. 3 is a configuration diagram of a temperature sensor circuit used in a conventional temperature monitoring system.

  Embodiments of a temperature monitoring system according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram showing an embodiment of a temperature monitoring system according to the present invention, which is an example applied to a conductor connection portion of a bus duct as a measured object.

  In FIG. 1, a temperature monitoring system according to the present invention includes a plurality of temperature sensors 1 for detecting the temperature of a measured object, a data collection device 5 connected to the temperature sensors 1 and a cable 3, and the data collection device. The controllers 6 and 7 for collecting and converting the information and the central monitoring device 8 are included.

  The plurality of temperature sensors 1 are directly installed on the measurement object 2a by a detachable bonding means. In FIG. 1, the DUT 2 a is a conductor connection part of the bus duct 2. The temperature sensor 1 measures the surface temperature of the measured object 2a itself. As a detachable bonding means used for the temperature sensor 1, a strong magnet such as a neodymium magnet is provided on the back surface of the temperature sensor. This temperature sensor 1 is also provided with an LED lamp, detects not only the temperature, and finally turns on the LED lamp when the temperature exceeds an arbitrarily set temperature, as well as a communication function for transmitting a signal to the central monitoring device 8. .

  Each temperature sensor 1 is connected to a data collection device 5 by a cable 3. The cable 3 from the data collection device 5 is branched by a T branch 4 and connected to each temperature sensor 1. In FIG. 1, four cables are arranged from the data collection device 5. The T-branch 4 uses a shielded junction, suppresses the generation of noise, and is provided with a strong magnet on its back surface so that it can be easily attached and detached. The cable 3 is a shielded LAN cable that is a shielded twisted pair cable. For this reason, measurement length can be extended and it can be extended to a maximum of 150 m.

  The data collection device 5 collects information from each temperature sensor 1. Since 15 temperature sensors 1 can be connected to one cable of the data collecting device 5, and the data collecting device 5 can be arranged with four cables per device, a total of 60 The temperature sensor 1 can be connected.

  The controller includes a zone controller 6 and a general controller 7. The zone controller 6 converts the signal from the data collection device 5 into IP. The integrated controller 7 is used as a gateway with the server, and can store trend data and save a log therein.

  The central monitoring device 8 is equipped with a general-purpose PC or server machine and can be monitored remotely. On the monitoring screen, in addition to the measured values of each measurement by the temperature sensor 1, a trend graph and alarm history can be confirmed. It is also possible to output it as a form depending on the situation.

  FIG. 2 is a configuration diagram of a temperature sensor circuit used in the temperature monitoring system according to the present invention. In FIG. 2, compared with the conventional method of FIG. 3, the transmission distance is greatly extended by changing the transmission method from the single-ended method to the differential transmission method.

  Moreover, since the termination resistor is provided, the transmission distance is greatly extended. A general termination is provided at both ends between the signal line and the GND line. However, since the data collection device 5 needs to provide a pull-up resistor between the signal line and the 5V resistance, the termination resistance is limited to the GND line. Can not be connected. Therefore, the transmission distance is greatly extended by adding a terminating resistor to 5 V at the node side final end.

  Further, a repeater circuit for improving noise margin is provided at the rear end of the host IC. By adopting an IC having hysteresis for the input IC pin of the repeater circuit, VIL and VIH are improved. When changing from L to H, it becomes H when it exceeds 3.5V, and when changing from H to L, it becomes L when it falls below 1.5V. Thus, by improving the input level, the noise margin is greatly improved.

  The temperature monitoring system according to the present invention can transmit information from a large number of temperature sensors over a long distance, and can detect a temperature change of each measured object accurately and quickly without causing malfunction due to noise. . Moreover, since the temperature sensor used in the temperature monitoring system according to the present invention is directly installed on the measured object by the detachable bonding means and the T-branch is also detachable, it can be easily applied to the existing measured object. Applicable to. Moreover, the temperature monitoring system according to the present invention is inexpensive because the system itself is simple.

  Therefore, the temperature monitoring system according to the present invention is not only for monitoring the temperature of the conductor connection portion of the bus duct, but also for temperature monitoring in a wide range of fields such as medical facilities such as newly established or existing hospitals, food factories, server rooms, and greenhouses. Preferably used.

1 Temperature Sensor 2 Bus Duct 2a Measured Body (Bus Duct Conductor Connection)
3 Cable 4 T branch 5 Data collection device 6 Zone controller 7 Integrated controller 8 Central monitoring device

Claims (4)

  A temperature having a plurality of temperature sensors for detecting the temperature of the object to be measured, a data collection device connected to the temperature sensors with a cable, a controller for collecting and converting information from the data collection device, and a central monitoring device A monitoring system, wherein the temperature sensor and the data collection device are connected by a cable, and the temperature sensor circuit used has a repeater circuit on the data collection device side, and the signal is differentially transmitted through a twisted pair wire. A temperature monitoring system comprising a plurality of pull-up termination resistors at the final ends of the temperature sensors.   The temperature monitoring system according to claim 1, wherein the cable is a shielded LAN cable and is connected to the plurality of temperature sensors by a T-branch.   The temperature monitoring system according to claim 1 or 2, wherein the temperature sensor is directly installed on the measurement object by a detachable bonding means.   The temperature monitoring system according to claim 1, wherein the object to be measured is a conductor connection part of a bus duct.

Images