The USB to RS232 converter board is most essential bridge needed to connect serial device to log the data to pc or laptop. If you have a development board like 8051, AVR, PIC or any other with serial UART or RS232 connector. Then use the USB to RS232 converter to connect these devices for programming or communication with the PC or Laptop.
Now a days most of the laptops does not have COM ports to connect directly with RS232 cable. So use i-labz USB to RS232 converter for interfacing. If you are planning to buy 8051,AVR,PIC or any other boards like GSM modem, GPS, Bluetooth, Finger print scanner or Ultrasonic distance finder then you must use USB to RS232 connector for connecting or troubleshooting with laptop.
To test the USB to RS232 converter use windows hiighper terminal (using winXP as OS) or terminal tool. The procedure to test to setup the highper terminal is explained in www.ilabzelectronics.com/blog. The USB to RS232 converter is also has the TTL outputs named as RX and TX on the board. This could be directly used to tap the serial outputs needed to connect with the TTL compatible interfacing devices. The drivers are provided in the download & installed the CP21XX chips at driver to connect this USB to RS232 Converter on PC or laptop.