Long distance card readers and other high current input/output devices connected to the access controller precautions

The common alternative to the conventional access control reader connected to the access controller of the large current input devices are: long-distance card reader and fingerprint meter or palm meter.

If you need to connect other external input devices that are not commonly used, please communicate with the blueprint technology department first and then proceed under our guidance.

The working current of the input device of an ordinary access control attendance card reader is usually 30-300 MA. Long-distance card readers typically operate at currents between 500 mah and 2A. The operating current of the fingerprint meter is between 300-1.5A.

The controller of Nabon is protected against high current at the power output outlet of the card reader. This protection mechanism helps to prevent the main power supply from being destroyed when the power line of the card reader is short circuited and will not be maliciously opened.

Scheme 1 External power supply connection method:

Purchase another power supply to supply power to the large current input device separately, and connect the GND of the other power supply to the GND of the original power supply of the controller with a thick wire.

The rated working current of the purchased power supply should be noted that it should be far greater than the nominal rated current of the large current input device, because the nominal working power supply of many equipment parameters is smaller than the actual working current, and there is generally no nominal impulse current, so the current of the purchased power supply should be reserved at least twice the power predegree, and it is recommended that you buy more than 5A switching power supply.

The output signal of the high-current input device should be in wiegand26 format, otherwise it cannot be connected to the controller of the blueprint. Why connect the GND of the two power supplies? Because the digital device needs the same zero potential reference, otherwise the signal will be unstable or the signal will be offset, sometimes the signal is received, sometimes the signal is not received.

Scheme 2 does not supply power to the input device from the controller, but directly from the main power supply?

Do not connect the +12V and GND power supply at the card reader position from the slave controller, but connect the power cable pairs of the high-current input devices to the +12V and GND of the original power supply.

The prerequisite for this connection is that the nominal value of the high-current input device is within 300-600 MA, the original power supply is only connected to less than two standard electric locks, and the power supply is only connected to a high-current device.

My personal suggestion is that plan one is much better than plan two. Option 2 is only suitable for use in certain situations, for the benefit of cost savings.