Quatech RS-232 - Manual (Page 37)

4800 4300 3300 1570 800 115.2
2000 1630 1100 900 330 230.4
1100 900 670 430 100 460.8
470 430 300 100 N/A 921.6
25%
trans
time
20%
trans
time
15%
trans
time
10%
trans
time
4%
trans
time
Maximum Load (pF)
Data Rate
(kbaud)
Note 1: The signal transition time ratio is defined as the
percentage of the unit interval or bit time (the inverse of the data
rate) that is occupied by the signal transitioning from -3V to +3V.
The EIA/TIA-232-E standard defines a maximum signal
transition time ratio of 4%; most RS-232 receivers will recognize
signal transitions with much larger ratios. With a 4% signal
transition time ratio, EIA/TIA-232-E is limited to a theoretical data
rate of 200 kbaud. If maximum signal transition time ratio is
extended to 10%, 15%, 20%, or even 25%, the maximum data rate
achievable using EIA/TIA-232-E can be increased past 200 kbaud.
Note 2: A typical value for capacitance per foot of standard cable
is 50 pF/ft.
ESC(LP)-100 User's Manual 31