Vaisala HMM105 - Manual (Page 19)

Chapter 2 _______________________________________________________________ I2C Interface
VAISALA ____________________________________________________________________ 17
Adjust
The Adjust command (ID 84h) controls the user adjustment sequence of
the HMM105.
Table 26 Adjust Invoke Message
Message Segment Length Content
I 2 C address 1 byte I 2 C address (write)
Command ID 1 byte Always 84h
Device address 1 byte See Table 5 on page 4
Frame length 1 byte Varies according to data length,
07h ... 0Bh.
Data 1 byte Adjustment subcommand.
See Table 28 below.
1 byte Parameter to be adjusted.
See Table 29 below.
4 bytes Value of parameter. Used only with
subcommands 2 and 3.
Checksum 2 bytes See section Checksum on page 9
Table 27 Adjust 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 84h
Device address 1 byte See Table 5 on page 4
Frame length 1 byte Always 07h.
Data 1 byte Return code. See Table 30 on page 18.
Checksum 2 bytes See section Checksum on page 9
Table 28 Adjustment Subcommands
Code Adjustment operation
0 Start 1 point adjustment
1 Start 2 point adjustment
2 Record measured point 1, reference value is given in parameter
3 Record measured point 2, reference value is given in parameter
4 Cancel adjustment (previous adjustment is reverted)
5 End (adjustment is saved and new values are taken in use)
6 Revert to factory calibration (clear user adjustment)
Table 29 Adjustment Parameters
Code Purpose
0 All parameters (valid with revert to factory calibration)
1 Not used
2 T
3 Not used
4 RH