How to create RS232 command on your own

You can create RS232 command on your own to rewrite serial number on Qisda projectors.

Step 1: Make sure you have the Serial number of the projector you want to rewrite.

Step 2: Please refer to the following image.

RS232 command has 4 Parts.

1. Start bit

2. Command

3. Serial number information

4. Check Sum

Step 4: Start bit and command will not change for all the projectors from Qisda.

Step 5: For Serial number information, please match the Alpha numeric serial number with the Ascii Table.

In the above example, Serial number is PRJ093045678

P = 50

R = 52

J = 4A

and so on....

Step 6: For Check Sum, you will need to add numbers from command to the end of Serial number. You can use the Calculator app on your computer with Programmer mode turned on with Hexadecimal option. 

Once you add all the alpha numeric, you will get a 3 digit result. Please exclude the first digit. The last 2 digits will be your Check Sum.

Step 7: Now you have the RS232 command to rewrite the Serial number on to the projector.

Note: RS232 command differs for each serial number

How to rewrite Serial number onto the projector.

Step 1: Download and install vController from the respective projectors Download page from ViewSonic website.

Below is an example of download page for PA503S.

https://www.viewsonic.com/global/products/projectors/PA503S#downloads

Step 2: Connect one end of the RS232 cable to projector’s RS232 port and other end to computer.

Step 3: Open vController and select Projector and under RS232 section, select com and Baud options.

Step 4: Click on Connect.

Step 5: Once the connection is successful, select Command icon on right top and choose Hex.

Step 6: Enter the RS232 command that you created with the Serial number and select Send.

Step 7: Restart the projector and check serial number information on OSD.