Quantum and Evolution Series Installation and Operating Handbook
8-28
Figures: Overhead rate with backward alarm (/ Overhead rate without backward alarm, if
different)
Main data channel rates
ESC rates 9.6kbps
16kbps
64kbps
256kbps
512kbps 1024kbps 2048kbps
2400
Baud
33.3%
20%
5% / 4.8%
1.25% /
1.19%
0.62% /
0.59%
0.39% *
0.39% *
4800
Baud
100% 50% 10% 2.5%
/
2.38%
1.25% /
1.19%
0.62% /
0.59%
0.39% *
9600
Baud
n/a 100% 20% 5%
/
4/76%
2.5% /
2.38%
1.25% /
1.19%
0.62% /
0.59%
19200
Baud
n/a n/a 50%
10%
5%
/
4.76%
2.5% /
2.38%
1.25% /
1.19%
38400
Baud
n/a n/a
100%
20%
10%
5%
/
4.76%
2.5% /
2.38%
The formula for deriving the overhead rate is moderately complex, and relies on many
different parameters. For other mixes of data rate and async settings the simplest way to
determine the overhead is to enter the parameters into a modem and then select
View/Config/Tx-Rx
. This screen shows the exact overhead percentage. Information on the
framed data rate, the data rate including any Reed-Solomon encoding and the final symbol
rate including the effects of the `inner ` FEC and modulation can be found under
View/Monitor/Tx-Rx
.
