Voltage sent over the pins can be in one of two states, On or Off.
On (binary value "1") means that the pin is transmitting a signal
between -3 and -25 volts, while Off (binary value "0") means that it is
transmitting a signal between +3 and +25 volts...
The electrical specifications of the serial port is contained in the EIA
(Electronics Industry Association) RS232C standard. It states many
parameters such as -
1.
A "Space" (logic 0) will be between +3 and +25 Volts.
2.
A "Mark" (Logic 1) will be between -3 and -25 Volts.
3.
The region between +3 and -3 volts is undefined.
4.
An open circuit voltage should never exceed 25 volts. (In Reference to GND)
5.
A short circuit current should not exceed 500mA. The driver should be
able to handle this without damage. (Take note of this one!)
serial port
Re: serial port
