Six frequently asked questions about LED display control card
The LED display control card is the core component of the LED graphic display. It is mainly responsible for receiving the picture display information from the serial port of the computer, placing it in the frame memory, and generating the serial display data and scanning required by the LED display according to the partition drive mode. Control timing. This article will analyze and answer the control card application problems encountered in practical applications to help industry users improve application efficiency.
1. How to judge whether the LED display control card is working normally?
Answer: After the control card is powered on, please observe the power indicator first. The red light is on, indicating that the 5V voltage has been connected. If it is not on, please turn off the 5V power immediately. Check whether the 5V working voltage is connected well, whether it is overvoltage, reverse connection, failure, output short circuit, etc. Please use a separate 5V power supply to power the control card. If the red light is not on, it needs to be repaired.
2. When the LED video wall control card is normal, why is the display screen no display or abnormal brightness?
Answer: After the LED video wall control card is connected to the display driver, the default is 16 scans. If there is no display, please check whether the data polarity and OE polarity settings in the control software are correct; if the brightness is abnormal, one line is particularly bright, indicating OE The setting is reversed, please set the OE correctly.
3. Why does the system prompt “Error occurred, transmission failed” when transmitting information to the LED display control card?
Answer: Please check whether the connection of the communication interface is correct, whether the jumper on the LED display control card jumps at the corresponding level position, and whether the parameters in “Control Card Settings” are correct. There is also whether the working voltage is too low, please use a multimeter to test to ensure that the voltage is above 4.5V.
4. Why can’t the display display normally after the information is loaded?
A: Check whether the scan output selection in “Control Card Settings” is correct.
5. Why is the communication not smooth when the 485 network is established?
Answer: Please check whether the connection method of the communication line is correct, and connect the communication lines of each screen to the computer interface by mistake, which will generate strong reflected waves and cause serious interference to the transmission signal. The correct connection method should be adopted, see “Communication Interface Usage and Precautions” for details.
6. How to solve the problem of poor communication when using GSM data transmission or remote dialing?
A: When the communication is not smooth after the connection, if you are not sure where the problem is, you can take the method of segmented detection.
First check whether there is a problem with the MODEM, disconnect the MODEM connected to the control card, and connect the MODEM to another computer, so that the MODEMs on the sending end and the receiving end are connected to the computer, and are separated from the control system. Download a software named “Serial Debug Assistant” from the Internet, and use it to set and debug the MODEM after installation. First, set the MODEM of the receiving end to automatic answering. The setting method is: open the serial port debugging assistant on both ends, and enter “ATS0=1 Enter” in the serial debugging assistant of the receiving end. This command can set the MODEM of the receiving end to automatic answering. If the setting is successful, the AA indicator on the MODEM will be on. If it does not light, the setting is unsuccessful, please check whether the connection between the MODEM and the computer is correct, and whether the MODEM is powered on.
After the automatic answering setting is successful, enter “the phone number of the receiving end, press Enter” in the serial debugging assistant of the sending end, and dial to the receiving end. At this time, some information can be passed from the sending end to the receiving end, or from the receiving end to the sending end. For some information, if the information received by both ends is normal, the communication connection has been established, and the CD indicator on the MODEM is on. If the above process is normal, it proves that the MODEM communication is normal and there is no problem.
After checking that there is no problem with the MODEM, if the communication is still not smooth, the problem may lie in the settings of the control card. Connect the MODEM to the control card, open the control card setting software on the sender side, click to read back the settings, check whether the serial port baud rate, serial port, protocol and other settings are correct, and click to write the settings after changing. Open the offline king software, set the corresponding communication interface mode and parameters in the communication mode, and finally send the script.