User Manual

16 MHX-2400 Operating Manual: Chapter 3 Configuration Options
The Master determines the
Wireless Link Rate. This
setting on all other modems
is ignored..
S Register 102 - Serial Baud Rate
The Serial Baud Rate is the current speed that the modem is using to
communicate with the DTE. When the AT command prefix is issued, the
modem performs an ‘autobaud’ operation and determines what the current
DTE baud rate is set to. The S register value returns the current setting of
the DTE baud rate.
The possible values are:
* 1 115200
2 57600
3 38400
4 28800
5 19200
6 14400
7 9600
8 7200
9 4800
10 3600
11 2400
It is generally advisable to choose the highest rate that your terminal
equipment will handle to maximize performance, unless a limitation on the
available bandwidth is desired. If the DTE is a personal computer, the port
can usually be used reliably at 115200. It is not possible to write values to
this register, since the instant another AT command is issued, the register
will revert to the current baud rate. Therefore, it is advisable to operate in
Command Mode at the desired baud rate for Data Mode.
S Register 103 - Wireless Link Rate
The Wireless Link Rate is the speed and optimization method for which
modems will communicate over the RF link. It is only necessary to set this
parameter on the Master unit. Units configured as Repeaters and Slaves will
ignore this setting, and adjust automatically to the rate of the Master.
The allowable settings are:
2 Fast without Forward Error Correction
*4 Fast with Forward Error Correction
Depending on the application requirements, each mode will provide
different throughput and performance. Appendix E. Performance Tables
give some indication of the performance to be expected in each mode.
In general, Forward Error Correction (FEC) reduces throughput, but in some
environments will actually increase throughput. FEC can reduce the number
of bad data packets, and hence reduce the need to retransmit.