User Manual

Page 25 of 90
CCT24
2.13 Serial Port Operation
CCT24 networks are often used for wireless communication of serial data. The CCT24 supports serial
baud rates from 1.2 to 460.8 kb/s. Listed in Table 2.13.1 below are the supported data rates and their
related byte data rates and byte transmission times for an 8N1 serial port configuration:
Baud Rate kb/s
Byte Data Rate kB/s
Byte Transmission Time ms
1.2
0.12
8.3333
2.4
0.24
4.1667
4.8
0.48
2.0833
9.6
0.96
1.0417
19.2
1.92
0.5208
28.8
2.88
0.3472
38.4
3.84
0.2604
57.6
5.76
0.1736
76.8
7.68
0.1302
115.2
11.52
0.0868
230.4
23.04
0.0434
460.8
46.08
0.0217
Table 2.13.1
To support continuous full-duplex serial port data flow, an RF data rate higher than the serial port baud
rate is required for FHSS. Radios transmissions are half duplex, and there are overheads related to
hopping frequencies, assembling packets from the serial port data stream, transmitting them, sending
ACK’s to confirm error-free reception, and occasional transmission retries when errors occur.
For example, consider a TDMA mode 2 system with one remote operating up to 20 miles away at
500 kb/s, with the BaseSlotSize parameter set to 64 bytes and the RemoteSlotSize parameter set to 64
bytes.