First, why does RS485 networking fail?
Causes of disconnected networks include:
1. The serial number of the device is duplicated or the serial number is set incorrectly. The serial number of each device registered in the computer software database cannot be duplicated; the serial number of the installed networking device cannot be duplicated (control software setting);
2. RS485 communication line A, B reversed, exchange can be;
3. The “ground†line of the signal reference is not connected, and often it is not connected and the data is lost, and the “ground†line can be connected.
4. The communication rate is different at both ends, or the verification mode is different at both ends.
5. The distance from the controller to the network extender exceeds the effective length (1200M);
6. Is the serial port of the computer normal, whether it is normally connected or occupied by other programs, and exclude these reasons and test again;
7. In the software settings, the device address number or serial port number (COM1, COM2) does not correspond to the actual setting or connection.
Second, why the network is not normal?
1. Occasional data loss: The "ground" cable must be connected.
2. Short communication distance: A. Because the twisted pair cable is not used. RS485 must use twisted pair (UTP) communication. When the communication line passes through an area with strong electromagnetic interference, a shielded twisted pair cable (Category V) should also be used. B. RS232---RS485 converters (modules) are generally no power supply, its drive capability is not strong, resulting in communication drive distance and a small number of device connections, should use active RS232-RS485 module or interface card .
3. There are few RS485 connection devices, and even more than five devices are not normal: The communication drive capability of the unused twisted pair, RS232-RS485 module is not enough, and the “ground†between the host computer and the device is disconnected; solution: again Connect all terminals' ground (signal reference ground) together. If the problem still exists: Replace the RS232-RS485 module. Still can not solve the problem, that is, the communication circuit part of a certain device has been damaged.
Third, how to increase the RS485 communication distance?
Increase the RS485/RS422 communication distance must use signal enhancement equipment.
Fourth, why did the manual door open button not respond?
The reasons are: 1. Button contact is not good; 2. The software does not set the button to open the door button, if not for the above two reasons, the controller has a problem, please contact the designated service point or return the factory to repair.
5. Why did you open the door by mistake?
The reasons are: Manually open the door to the wrong touch, or its connection line is longer, there is a broken skin, the wire has a wrong contact.
6. Why is the light of the card reader dark and the electric lock is weak?
Possible causes: The power supply is insufficient, causing the controller, card reader, and electric lock to not work properly.
7. When the card is near the card reader, how does the controller's buzzer do not ring and the controller's relay does not work?
Possible causes: 1. The connection between the card reader and the controller is incorrect; 2. The reader-to-controller circuit exceeds the effective length (100M); 3. The line is seriously interfered and the card reader data cannot be transmitted to the control. Device.
8. When the valid card is near the card reader, the buzzer sounds and the controller relay works. Why can't the door be opened?
Possible causes: 1. The connection between the controller and the electric lock is incorrect; 2. The electric control lock is faulty; 3. The mechanical locking of the bolt and the latch occurs.
Nine, the use of access control has been normal, suddenly found one day why all valid cards can not open the door (becomes invalid card)?
Possible reasons: The operator has initialized the access controller or other reasons, causing the controller to execute an initialization command.
Information from the Beijing Hong An Xiang Yu a professional iris recognition attendance machine production equipment manufacturers price concessions.
Causes of disconnected networks include:
1. The serial number of the device is duplicated or the serial number is set incorrectly. The serial number of each device registered in the computer software database cannot be duplicated; the serial number of the installed networking device cannot be duplicated (control software setting);
2. RS485 communication line A, B reversed, exchange can be;
3. The “ground†line of the signal reference is not connected, and often it is not connected and the data is lost, and the “ground†line can be connected.
4. The communication rate is different at both ends, or the verification mode is different at both ends.
5. The distance from the controller to the network extender exceeds the effective length (1200M);
6. Is the serial port of the computer normal, whether it is normally connected or occupied by other programs, and exclude these reasons and test again;
7. In the software settings, the device address number or serial port number (COM1, COM2) does not correspond to the actual setting or connection.
Second, why the network is not normal?
1. Occasional data loss: The "ground" cable must be connected.
2. Short communication distance: A. Because the twisted pair cable is not used. RS485 must use twisted pair (UTP) communication. When the communication line passes through an area with strong electromagnetic interference, a shielded twisted pair cable (Category V) should also be used. B. RS232---RS485 converters (modules) are generally no power supply, its drive capability is not strong, resulting in communication drive distance and a small number of device connections, should use active RS232-RS485 module or interface card .
3. There are few RS485 connection devices, and even more than five devices are not normal: The communication drive capability of the unused twisted pair, RS232-RS485 module is not enough, and the “ground†between the host computer and the device is disconnected; solution: again Connect all terminals' ground (signal reference ground) together. If the problem still exists: Replace the RS232-RS485 module. Still can not solve the problem, that is, the communication circuit part of a certain device has been damaged.
Third, how to increase the RS485 communication distance?
Increase the RS485/RS422 communication distance must use signal enhancement equipment.
Fourth, why did the manual door open button not respond?
The reasons are: 1. Button contact is not good; 2. The software does not set the button to open the door button, if not for the above two reasons, the controller has a problem, please contact the designated service point or return the factory to repair.
5. Why did you open the door by mistake?
The reasons are: Manually open the door to the wrong touch, or its connection line is longer, there is a broken skin, the wire has a wrong contact.
6. Why is the light of the card reader dark and the electric lock is weak?
Possible causes: The power supply is insufficient, causing the controller, card reader, and electric lock to not work properly.
7. When the card is near the card reader, how does the controller's buzzer do not ring and the controller's relay does not work?
Possible causes: 1. The connection between the card reader and the controller is incorrect; 2. The reader-to-controller circuit exceeds the effective length (100M); 3. The line is seriously interfered and the card reader data cannot be transmitted to the control. Device.
8. When the valid card is near the card reader, the buzzer sounds and the controller relay works. Why can't the door be opened?
Possible causes: 1. The connection between the controller and the electric lock is incorrect; 2. The electric control lock is faulty; 3. The mechanical locking of the bolt and the latch occurs.
Nine, the use of access control has been normal, suddenly found one day why all valid cards can not open the door (becomes invalid card)?
Possible reasons: The operator has initialized the access controller or other reasons, causing the controller to execute an initialization command.
Information from the Beijing Hong An Xiang Yu a professional iris recognition attendance machine production equipment manufacturers price concessions.
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