Product manual
9XTend‐PKG‐R™RS‐232/485RFModem–ProductManualv1.2.4
©2005MaxStream,Inc.ConfidentialandProprietary 29
HT (Time before Wake-up Initializer) Command
<Sleep (Low Power)> Set/read time of inactivity
(no serial or RF data is sent or received) before a
wake-up initializer is sent by a TX modem. HT
should be set shorter than inactivity timeout [ST
Command] time of any RX modems operating in
Cyclic Sleep (SM=4-8). The wake-up initializer
sent by the TX modem instructs all RX modems to
remain awake to receive RF data.
From the RX modem perspective: After HT time
elapses and the inactivity timeout [ST Command]
is met, the RX modem goes into cyclic sleep. In cyclic sleep, the RX modem wakes once per sleep
interval [SM Command] to check for a wake-up initializer. When a wake-up initializer is detected,
the modem stays awake to receive data. The wake-up initializer must be longer than the cyclic
sleep interval to ensure that sleeping modems detect incoming data.
AT Command: ATHT
Binary Command: 0x03 (3 decimal)
Parameter Range: 0 – 0xFFFF
[x 100 milliseconds]
Default Parameter Value: 0xFFFF (wake-up
initializer will not be sent)
Number of bytes returned: 2
Related Commands: LH (Wake-up Initializer
Timer), SM (Sleep Mode), ST (Time before
Sleep)
When HT time elapses, the TX modem knows it needs to send a wake-up Initializer for all RX
modems to remain awake and receive the next transmission.
HV (Hardware Version) Command
AT Command: ATHV
Parameter Range (read-only): 0 – 0xFFFF
Default Parameter Value: 0x14FF (5375d)
Number of bytes returned: 2
<Diagnostics> HV Command is used to read the
hardware version of the modem.
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 modem. Modems must have matching VIDs
in order to communicate.
KY (AES Encryption Key) Command
<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
modem 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).
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
A modem 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 modem with a key will still receive
unencrypted data sent from a modem 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.