Technical Support
  • Q A magnetic sensor will be damaged by excessive current
    Do not exceed specification, permanent damage to the sensor may occur.

  • Q Why is a magnetic sensor damaged or malfunctioned?
    1. For solid-state type sensors, polarity must also be observed. Connect brown wire to the positive ( + ) and the blue to the negative ( - ) of DC power source.
    The black wire must connect to the load only. If the black wire is accidentally connected to the power source, permanent damage to the sensor may occur.


    2. For solid-state type sensors,polarity must also be observed.

    Connect brown wire to the positive ( + ) and the blue to the negative ( - ) of DC power source. The black wire must connect to the load only.

    If the black wire is accidentally connected to the power source, permanent damage to the snesor may occur.


    3. An external protection circuit may be required if the magnetic sensor is used with inductive load, such as relay or solenoid.

    For DC inductive load, attach an external diode parallel to the load.

     Use R-C circuit parallel with AC inductive load as illustrated below.


    4.   Keep sensors away from strong magnetic field to prevent malfunctions.

    5.   Reed sensors are without protection circuit.

    When a reed sensor is used with a capacitive load or with more than 5 meters lead wire, the life of the contact will be shortened.
    (especially when the switch is always ON)

    Note: Please install a surge suppressor SR-1 within 1 meter or an inductor (560 ~ 1000 μH) in series of the sensor to prevent damage.


  • Q LED indicator does not work
    For reed sensor type sensors, polarity must also be observed for the proper function of LED. Connect the brown wire in series with load to positive ( + ) and the blue wire to negative ( - ) of power source. If the polarity is reversed, reed sensor remain functional but LED will remain in " OFF " state.
  • Q A pressure sensor will be damaged by excessive current

    When using a 2-wire type pressure sensor ( KP101 / 102 & KP10A / 10B ), please make sure it is connected to a DC power source and a proper resistance load. Otherwise excessive current will damage the sensor permanently.

    Always connect the brown wire to the positive ( + ), blue wire to the negative ( - ).

    Permanent damages to the pressure sensor will occur if the connections are reversed.

  • Q Why is a pressure sensor damaged or malfunctioned?
    1. When using with inductive load ( such as relay or solenoid ), please install a flyback diode across the load to remove surge and polarity must be observed or damages to pressure sensor may occur.

    Before sensor installation or removal, please make sure the power is OFF and pressure in pipe has been released, released to avoid personal injuries, sensor damage or other losses.
    Please separate the power supply of a variable frequency driver or a motor driver from the pressure power supply to avoid noise affect the pressure sensor normal operation.
    Do not use corrosive gases or liquids as pressure media.
  • Q How to improve stability of the pressure sensor?
    To improve stability of the pressure sensor and the whole circuit in general, it is recommended to properly ground the DC power source.

  • Q How to install NPN/PNP transducer on PLC?
    1.General PLC (Programmable Logic Computer) could select input type NPN or PNP, by connects S/S to 24V or 0V respectively.
    ■ NPN input:
    S/S connects to 24V.
    ■ PNP input:
    S/S connects to 0V.

    2.Considering PLC power supply ability, please apply external power to sensors rather than internal power of PLC.

    Attention:Please notice that GND of external power shall be connected to GND of PLC.
  • Q MODBUS wiring?

    Modbus is one kind of protocols that machine can transfer data through this method. Generally speaking, MODBUS is to machines what language is to human beings.

    Communication protocol is software level protocol, and different devices exchange data through the same protocol.

    Then machine needs physical port to transfer data, such as EIA 485(RS485)、EIA422(RS422)、EIA232(RS232) or RJ45 Ethernet.

    Attention:Device with RS485 port does not mean it must support Modbus Protocol. Please contact Device provider for more information.

    RS485 sign

    RS485 2 wires
    Receive D
    Transmit D+

    2.Connection diagram


    3.Examples:KP75口-02/04 Circuit wiring diagrams
    MODBUS wiring method: Wire B+ connects with D+(RS485+) of your own equipment.  Wire A- connects with D-(RS485-) of your own equipment.

    4.Make sure the principle of connection is correctly when do wiring, and do not use T type wiring method, star type wiring method or any other wiring method for convenience.

    5.Keep away from high noise source when wiring. Do not use the same groove as the power wire uses in the distribution box. Externally, keep as far away as possible from devices which have electromagnetic radiation.
    The transfer wire need to use shielded twisted pair wire. Normal twisted pair wire can be used when conducting short distance communication in low noise environment to reduce cost. But in high noise environment, long distance communication or in case of high communication quality is required, the dedicated transfer wire for RS-485 is recommended. It may make higher budget, but the communication quality will be improved magnificently.

    6.Terminal resistances must be parallel connected to the two terminal points of the whole communication circuit. For the twisted pair wire used by RS-485 interface, the terminal resistances should choose 120Ω 1/2 W ones.

  • Q Final check before transmitting data

    1. Check whether the communication software is working properly, including whether the communication parameters (such as ID, baud rate, check bit, delay, time-out setting) are correctly.
    2. Reduce environmental interferences.
    3. Re-wire the transfer wire, and avoid noise source.
    • ID:ID can only be identical.
    • Baud、Parity Check Bit:Ever part of system setting should be same.
    • Delay Time:Short delay time interval may cause data lose.
    • Time out:1000~500ms are recommended, depending on devices.

    If everything on the system is done correctly and communications still do not work, please contact PLC provider for more PLC communication setting details.

  • Q LED on magnetic sensor does not work

    Check power supply type (AC or DC) of product

    ■  AC-powered product
        Sensor works:LED is out of order. Please send back for examination.
        Sensor doesn't work:Please refer《The Malfunction of Magnetic Sensor》

    ■  DC-powered product
         Sensor works:Check the polarity of wiring.
          — Wrong:Please correct it. Please refer to the figure below
          — Correct:Please send back for examination.
         Sensor doesn't work:Please refer《The Malfunction of Magnetic Sensor》