<P> In the book PC 97 Hardware Design Guide , Microsoft deprecated support for the RS - 232 compatible serial port of the original IBM PC design . Today , RS - 232 has mostly been replaced in personal computers by USB for local communications . Advantages compared to RS - 232 are that USB is faster , uses lower voltages , and has connectors that are simpler to connect and use . Disadvantages of USB compared to RS - 232 are that USB is far less immune to electromagnetic interference ( EMI ) and that maximum cable length is much shorter ( 15 meters for RS - 232 v.s. 3 - 5 meters for USB depending on USB speed used ) . </P>
<P> In the book PC 97 Hardware Design Guide , Microsoft deprecated support for the RS - 232 compatible serial port of the original IBM PC design . Today , RS - 232 has mostly been replaced in personal computers by USB for local communications . Advantages compared to RS - 232 are that USB is faster , uses lower voltages , and has connectors that are simpler to connect and use . Disadvantages of USB compared to RS - 232 are that USB is far less immune to electromagnetic interference ( EMI ) and that maximum cable length is much shorter ( 15 meters for RS - 232 v.s. 3 - 5 meters for USB depending on USB speed used ) . </P>
what is the maximum length of a standard rs-232 cable
what is the maximum length of a standard rs-232 cable
15 meters
15 meters