9XTend™
OEM
RF
Module
–
Product
Manual
v1.2.4
©
2005
MaxStream,
Inc.
Confidential
&
Proprietary
25
HV (Hardware Version) Command
AT Command: ATHV
Parameter Range (read-only): 0 – 0xFFFF
Number of bytes returned: 2
<Diagnostics> HV Command is used to read the
hardware version of the module.
ID (Modem VID) Command
AT Command: ATID
Binary Command: 0x27 (39 decimal)
Parameter Range:
0 – 0x7FFF (user-settable)
0x8000 – 0xFFFF (factory-set)
Default Parameter Value: 0x3332 (13106d)
Number of bytes returned: 2
<Networking & Security> ID Command is used to
set/read the VID (Vendor Identification Number)
of the module. Modules must have matching VIDs
in order to communicate.
KY (AES Encryption Key) Command
AT Command: ATKY
Binary Command: 0x3C (60 decimal)
Parameter Range:
0 – (any other 64-digit hex valid key)
Default Parameter Value: 0 (disabled)
Number of bytes returned: 2
Number Base: Always Hexadecimal
<Networking & Security> KY Command is used to
set the 256-bit AES (Advanced Encryption
Standard) key for encryption/decryption of data.
Once set, the key cannot be read out of the
module by any means. The entire payload of the
packet is encrypted using the key and the CRC is
computed across the ciphertext. When encryption
is turned on, each packet carries an additional 16
bytes to convey the random CBC Initialization
Vector (IV) to the receiver(s).
A module with the wrong key (or no key) will still receive encrypted data, but the resultant data
driven out the serial port will be meaningless. Likewise, a module with a key will still receive
unencrypted data sent from a module without a key, but the output will be meaningless.
Because CBC mode is utilized, repetitive data appears different in different transmissions due to
the randomly-generated IV.
LH (Wake-up Initializer Timer) Command
<Sleep (Low Power)> LH Command is used to
set/read the duration of time for which the wake-
up initializer is sent. When receiving modules are
put into Cyclic Sleep Mode, they power-down
after a period of inactivity [specified by ST (Time
before Sleep) Command] and will periodically
awaken and listen for transmitted data. In order
for the receiving modules to remain awake, they
must detect ~35ms of the wake-up initializer.
LH Command must be used whenever a receiver
is operating in Cyclic Sleep Mode. This lengthens the Wake-up Initializer to a specific amount of
time (in tenths of a second). The Wake-up Initializer Time must be longer than the cyclic sleep
time that is determined by SM (Sleep Mode) Command. If the wake-up initializer time were less
than the Cyclic Sleep interval, the connection would be at risk of missing the wake-up initializer
transmission.
AT Command: ATLH
Binary Command: 0x0C (12 decimal)
Parameter Range: 0 – 0xFF
[x
100
milliseconds]
Default Parameter Value: 1
Number of bytes returned: 1
Related Commands: HT (Time before Wake-up
Initializer), SM (Sleep Mode), ST (Time before
Sleep)
Refer to Figures 3.1 & 3.2 of the SM Command description to view diagrams of correct and
incorrect configurations. The images help visualize the importance that the value of LH be greater
than the value of SM.
