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 computer serial port, putting it into 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 actual applications to help industry users improve application efficiency.
1. How to judge whether the control card is working normally?
Answer: After the control card is powered on, please observe the power indicator first. The red light is on to indicate that the 5V voltage is connected. If it is not on, please turn off the 5V power supply 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 control card is normal, why does the display have no display or the brightness is abnormal?
Answer: After the 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 that the OE setting is reversed , Please set OE correctly.
3. Why does the system prompt "An error occurred and the transmission failed" when sending information to the control card?
Answer: Please check whether the communication interface is connected correctly, whether the jumper on the control card jumps to the corresponding level position, and whether the various parameters in the "control card settings" are correct. Also, whether the working voltage is too low, please use a multimeter to test, first make sure the voltage is above 4.5V.
4. Why can't the screen display normally after the information is loaded?
Answer: Check whether the scan output selection in "Control Card Settings" is correct.
5. Why is the communication not smooth when the 485 network is connected?
Answer: Please check whether the connection method of the communication line is correct. Connect the communication lines of each screen to the computer interface by mistake. This will generate strong reflected waves and cause serious interference to the transmission signal. The correct connection method should be adopted, see "Communication Interface Use and Precautions" for details.
6. How to solve the problem of poor communication when using GSM data transmission or remote dialing?
Answer: When the communication is not smooth after connection, if you are not sure where the problem is, you can adopt the method of segmented detection.
First check if there is a problem with the MODEM, disconnect the MODEM connected to the control card, and connect this MODEM to another computer, so that the MODEM at the sending end and the receiving end are both connected to the computer and leave the control system. Download a software called "Serial Debug Assistant" from the Internet, and use it to set up and debug the MODEM after installation. First set the MODEM of the receiving end to automatic response. The setting method is: open the serial debugging assistant at 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 answer. If the setting is successful, the AA indicator on the MODEM will be on. If it is not on, 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 auto answer is set successfully, enter "receiving end phone number, press Enter" in the serial debugging assistant of the sending end to dial to the receiving end. At this time, you can pass some information from the sending end to the receiving end, or from the receiving end to the sending end. For some information, if the information received at both ends is normal, the communication connection has been established, and the CD indicator on the MODEM is on at this time. 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 control card settings. Connect the MODEM to the control card, open the control card setting software at the sender, click Read Back Settings, check whether the settings of the serial port baud rate, serial port, protocol, etc. are correct, and click Write Settings after changing. Open the offline king software, set the corresponding communication interface mode and parameters in the communication mode, and finally transmit the script.
