Vaisala HMM105 - Manual (Page 18)

Technical Reference _________________________________________________________________
16 ________________________________________________________________ M211638EN-A
Get_Parameter_Info
The Get_Parameter_Info command (ID 83h) reads the properties of a
single parameter from the HMM105. The command is useful for adapting
to parameters that have been added in a new software version. If the
requested parameter ID is not valid, data type Unknown Parameter ID
is returned.
Table 22 Get_Parameter_Info Invoke Message
Message Segment Length Content
I 2 C address 1 byte I 2 C address (write)
Command ID 1 byte Always 83h
Device address 1 byte See Table 5 on page 4
Frame length 1 byte Always 06h.
Data 1 byte Parameter ID
Checksum 2 bytes See section Checksum on page 9
Table 23 Get_Parameter_Info Response Message
Message Segment Length Content
I 2 C address 1 byte I 2 C address (read)
Status 1 byte See section Status Byte on page 9.
Command ID 1 byte Always 83h
Device address 1 byte See Table 5 on page 4
Frame length 1 byte Always 12h.
Data 1 byte Parameter ID
1 byte Parameter datatype. See Table 24
below.
1 byte Parameter length in bytes.
1 byte Parameter persistence. Describes if the
parameter value is volatile (lost at reset)
or non-volatile (survives reset). See
Table 25 below.
8 bytes Parameter name. If the name is shorter
than 8 bytes, extra bytes are filled with
00h.
Checksum 2 bytes See section Checksum on page 9
Table 24 Parameter Data Types
Code Meaning
0 Unknown parameter ID
1 Byte
2 Integer (16-bit)
3 Unsigned Integer (16–bit)
4 Float (32-bit)
5 String
Table 25 Parameter Persistence
Code Meaning
0 Void
1 Volatile
2 Non volatile