User's Manual

9XTend™ OEM RF Module - Product Manual v2.x6x
© 2010 Digi Internatonal, Inc. 23
BD (Interface Data Rate) Command
<Serial Interfacing> The BD command is used to
set and read the serial interface data rate (baud
rate) used between the RF module and host. This
parameter determines the rate at which serial
data is sent to the module from the host. Modified
interface data rates do not take effect until the CN
(Exit AT Command Mode) command is issued and
the system returns the 'OK' response.
When parameters 0-8 are sent to the module, the
respective interface data rates are used (as
shown in the table on the right).
The RF data ra
te is not affected by the BD param-
eter. If the interface data rate is set higher than
the RF data rate, a flow control configuration may
need to be implemented.
The range between standard and non-standard
baud rates (0x09 - 0x38) is invalid.
Non-standard Interface Data Rates: 
Any value above 0x38 will be interpreted as an
actual baud rate. When a value above 0x38 is
sent, the closest interface data rate represented
by the number is stored in the BD register. For example, a rate of 19200 bps can be set by send-
ing the following command line "ATBD4B00". NOT
E: When using Digi’s X-CTU Software, non-stan-
dard interface data rates can only be set and read using the X-CTU ‘Terminal’ tab. Non-standard
rates are not accessible through the ‘Modem Configuration’ tab.
When the BD command is sent with a non-standard interface data rate, the UART will adjust to
accommodate the requested interface rate. In most cases, the clock resolution will cause the
stored BD parameter to vary from the parameter that was sent (refer to the table below). Reading
the BD command (send "ATBD" command without an associated parameter value) will return the
value actually stored in the module’s BD register
.
BR (RF Data Rate) Command
<RF Interfacing> The BR command is used to set
and read the RF data rate (rate that RF data is
transmitted over-the-air) of the module.
Parameters Sent Versus Parameters Stored
BD Parameter Sent (HEX) Interface Data Rate (bps) BD Parameter Stored (HEX)
000210
4002,914
7002,5117
B21003C21
702B1002,511002C1
AT Command: ATBD
Binary Command: 0x15 (21 decimal)
Parameter Ranges: 0 - 8 (standard rates)
0x39 - 0x1C9C38 (non-standard rates)
Parameter Configuration (bps)
01200
12400
24800
39600
419200
538400
657600
7 115200
8 230400
Default Parameter Value: 3
Non-standard baud rates supported as of
firmware v2.x20
Number of bytes returned: 4
AT Command: ATBR
Binary Command: 0x39 (57 decimal)
Parameter Range:0 - 1
Parameter
Baud (bps)
Configuration
09600
1 115200
Default Parameter Value:1
Number of bytes returned: 1