Linx Technologies HUM-xxx-DT - Manual (Page 28)

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Read AES Key - Command Code = 43
This command reads out the AES key currently being used by the module.
This can only be read out if the module is an Access Point. It cannot be
read out of End Devices or Range Extenders.
This reads out the key in volatile memory, which is what is currently being
used to encrypt packets. This can be different from what is in non-volatile
memory if the Write AES Key command has been used to change it.
If an error occurs, such as trying to read the key from an ED, the response
is 3C 43 01 3E.
Write AES Key - Command Code = 44
This command writes the AES key into the module’s volatile memory. This
key is used to encrypt packets as soon as the write is completed.
The key is written MSB first. The response parameter indicates if the
command was successful (00) or if there was an error (01).
Read Module Temperature - Command Code = 47
This command reads out the value from the module’s internal temperature
sensor.
The temperature in degrees Celsius is calculated with the following formula.
For example, if the module returns TempH = 0x54 and TempL = 0x09 then:
T = {[(0x54 x 16) + 0x09] x 1250 / 2047 – 755} / 2.54 = 28.035°C
The Status parameter indicates if the command was successful (00) or if
there was an error (01).
Read AES Key Command and Response
Command
Start Command End
3C 43 3E
Response
Start Response Param 1 ... Param 16 End
3C 43 KeyMSB ... KeyLSB 3E
Figure 53: Read AES Key Command and Response
Write AES Key Command and Response
Command
Start Command Param 1 ... Param 16 End
3C 44 KeyMSB ... KeyLSB 3E
Response
Start Response Param 1 End
3C 44 Status 3E
Figure 54: Write AES Key Command and Response
Read Module Temperature Command and Response
Command
Start Command End
3C 47 3E
Response
Start Response Param 1 Param 2 Param 3 End
3C 47 TempH TempL Status 3E
Figure 55: Read Module Temperature Command and Response
( ) ( )
16 1250
755
2047
2.54
TempH TempL
T
× + ×
−
=