File : CS-SUP-MUTI-WTHERMAPP-E01.sxw
5.1.3 Setting of the probe coefficient parameters
The precision of DALLAS probes is indicated by the manufacturer as ±0.5°C (-10°C to +85°C) and requires
no calibration before use.
However, it is possible to improve this precision if the user wishes to calibrate the probe. In this case, the
WaveTherm module contains a 32-byte memory zone for storage of transfer coefficients after calibration.
Initially, two parameters was created (size: 2 bytes per parameter), each one being able to store the value of
a coefficient of transfer.
After calibration, this allowed to refine measurement with a 2 degrees polynomial to the maximum.
Thereafter, a more important memory area was implemented, in order to store user data. Users can use this
area for whatever they want, but in order to increase the measurement precision, this 32-bytes area allows to
store a more significant number of coefficients.
Consequently the polynomial used can be superior degrees to 2; and allows to obtain a finer sleeking of
information. Management of this memory area is described further in chapter 7.1.5.
Remark :
To maintain compatibility with old versions of the modules (Is)Thermeter), the storage
parameters of the coefficients are always existing, and are accessible by commands of reading and
writing of internal parameters.
Parameter 0x25 : parameter A relating to sensor 1
Parameter 0x26 : parameter B relating to sensor 1
Parameter 0x27 : parameter A relating to sensor 2
Parameter 0x28 : parameter B relating to sensor 2
WaveTherm modules – application handbook
page 16 of 65
