Digi XBee-PRO 900 Instruction Manual page 28

XBee‐PRO® 900 OEM RF Modules
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AT Command
API Identifier Value: (0x08)
Allows for module parameter registers to be queried or set.
AT Command Frames
Start Delimiter Length
0x7E MSB LSB
API Identifier
Frame ID (Byte 5)
Identifies the UART data frame for the host to
correlate with a subsequent ACK (acknowledgement).
If set to '0', no response is sent.
Example: API frames when reading the NJ parameter value of the module.
Byte 1 Bytes 2-3
0x7E 0x00 0x04
Start Delimiter Length*
* Length [Bytes] = API Identifier + Frame ID + AT Command
** "R" value was arbitrarily selected.
Example: API frames when modifying the NJ parameter value of the module.
Byte 1 Bytes 2-3 Byte 4
0x7E 0x00 0x05
Start Delimiter Length* API Identifier
* Length [Bytes] = API Identifier + Frame ID + AT Command + Parameter Value
** "M" value was arbitrarily selected.
A string parameter used with the NI (Node Identifier), ND (Node Discover) and DH (Destination
Address High) command is terminated with a 0x00 character.
AT Command - Queue Parameter Value
API Identifier Value: (0x09)
This API type allows module parameters to be queried or set. In contrast to the "AT Command" API
type, new parameter values are queued and not applied until either the "AT Command" (0x08) API
type or the AC (Apply Changes) command is issued. Register queries (reading parameter values)
are returned immediately.
AT Command Frames
(Note that frames are identical to the "AT Command" API type except for the API identifier.)
Start Delimiter Length
0x7E MSB LSB
API Identifier
Frame ID (Byte 5)
Identifies the UART data frame for the host to
correlate with a subsequent ACK (acknowledgement).
If set to '0', no response is sent.
© 2008 Digi International, Inc.
Frame Data Checksum
API-specific Structure 1 Byte
Identifier-specific Data
0x08 cmdData
AT Command (Bytes 6-7)
Command Name - Two
ASCII characters that
identify the AT Command.
Byte 4 Byte 5
0x08 0x52 (R) 0x4E (N) 0x4A (J)
API Identifier Frame ID**
Byte 5 Bytes 6-7
0x08 0x4D (M) 0x4E (N) 0x4A (J)
Frame ID** AT Command
Frame Data Checksum
API-specific Structure 1 Byte
Identifier-specific Data
0x09 cmdData
AT Command (Bytes 6-7)
Command Name - Two
ASCII characters that
identify the AT Command.
Parameter Value (Byte(s) 8-n)
If present, indicates the requested parameter
value to set the given register.
If no characters present, register is queried.
Bytes 6-7 Byte 8
0x0D
AT Command Checksum
Bytes 8 Byte 9
0x40 0xD2
Parameter Value Checksum
Parameter Value (Byte(s) 8-n)
If present, indicates the requested parameter
value to set the given register.
If no characters present, register is queried.
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