9XTend
‐
NEMA™
RS
‐
232/485
RF
Modem
–
Product
Manual
v2.x4x
[2007.01.04]
©
2007
MaxStream,
Inc.,
Confidential
&
Proprietary
‐
All
Rights
Reserved
30
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 modem and host. This
parameter determines the rate at which serial
data is sent to the modem 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 modem, the
respective interface data rates are used (as
shown in the table on the right).
The RF data rate 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 sending
the following command line "ATBD4B00". NOTE: When using MaxStream’s X-CTU Software, non-
standard interface data rates can only be set and read using the X-CTU ‘Terminal’ tab. Non-stan-
dard 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 modem’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 modem.
Parameters
Sent
Versus
Parameters
Stored
BD Parameter Sent (HEX)
Interface Data Rate (bps)
BD Parameter Stored (HEX)
0
1200
0
4
19,200
4
7
115,200
7
12C
300
12B
1C200
115,200
1B207
AT Command: ATBD
Binary Command: 0x15 (21 decimal)
Parameter Ranges: 0 - 8 (standard rates)
0x39 - 0x1C9C38 (non-standard rates)
Parameter
Configuration (bps)
0
1200
1
2400
2
4800
3
9600
4
19200
5
38400
6
57600
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
0
9600
1
115200
Default Parameter Value:1
Number of bytes returned: 1
