User manual

OPERATION MANUAL
Technical changes reserved
0141 0316-194 27.08.2015
Humidity temperature sensor
with serial interface
EXCEL™
If you want to use EXCEL for evaluation, then operate the control
button EXCEL before start of recording, so that suitable decimal
separation characters and eld separators are inserted. The created
le is compatible with CSV-Format. In order to display the measured
data, you can use graphic tools, for example, the diagram-assistant.
However, other programs can also be used to evaluate the measured
data.
Calibration
Format of data transfer
The interface works at a data rate of 4800 Baud, 8 data-bits, no parity
and one stop bit.
The transfer of useful data takes place in lines. All characters are
ASCII coded. All information is sent continuously without separation
characters. In a line, only information of one channel is transferred.
At the end of the line, the last two ASCII characters are sent for
the check sum (CRC) of the current line. Each line closes with the
character ‘Carriage return’ ‘<CR>´. Several lines form a data-block. A
data-block can have the following contents, for example:
@<CR>
I01010100B00725030178<CR>
V010892A1<CR>
I02020100B00725030148<CR>
V0216B0EA<CR>
$<CR>
The data block has a following structure:
• A synchronization pattern for the beginning of a Data block. For
synchronization, the sequence ´@ <CR>´ is used.
• The conguration data (´Identier´) of a channel. The data line
begins with the character ‘I’, followed by the logical channel
number, and then followed by conguration data and the Sensor
serial number. The line is closed with the check sum and the
character <CR>.
• The measured values of a channel. The data line begins with the
character ´V´, followed by the logical channel number, followed
by useful data. Only numerical measurement values and the
check sum (CRC) at the end of the line, are transferred. All other
information like number format, number of characters, physical
unit, etc. are contained in the conguration data (sensor coding).
• The conguration data and measurement values follow the same
scheme for all other channels.
• The continuation character ´$´ <CR>´ is sent at the end of a
data-block.
Structure of conguration dataline
The conguration data line contains all information of the sensor wor-
king on the corresponding channel. The line has a following structure:
• Identication character ´I´ at the beginning of the line.
• 8 bits (two ASCII characters) logical channel number. The logical
channel number is used to co-relate conguration data with the
measured values. In the Humidity-Temperature module, the tem-
perature values are transmitted through channel 01 and humidity
values are transmitted through channel 02.
• 8 bits (two ASCII characters) physical sensor coding. Based on
sensor coding, the number format, scale, physical unit and allo-
wable range of values are specied. For the described device,
sensor coding is 01 for temperature channel and 02 for humidity
channel.
• 8 bits (two ASCII characters) hardware coding (type of the
measurement sensor). The Temperature/Humidity module has
the code number 01.
• 48 bits (twelve ASCII characters) serial number of the sensor.
Each serial number is allotted only once.
• 8 bits (two ASCII characters) CRC (check sum)
• ´<CR>´ as line termination
Structure of measured values datalines
The measured value dataline contains the current measurements of
the sensor operating on the corresponding channel. All information
are represented in binary and is transferred in ASCII coded format
without separation characters. For the sensor marking 01, the line
has following a structure:
• Identication character ´V´ at the beginning of the line
The module is supplied in calibrated condition.
The accuracy at 23 °C is of the order of ±0.3 °K
and ±2% RH. Under normal operating conditions,
it is not necessary to again calibrate the module.
The measuring accuracy of humidity measurement
portion can be done by the end user with the salt
reference cells available as special accessories.
The checkup must be done in temperature stable
environment.
In case, the measured value does not match with the
desired value of the cell, the device should be sent
to our calibration laboratory for checkup.
Humidity temperature sensor
with serial interface
B+B Thermo-Technik GmbH | Heinrich-Hertz-Straße 4 | D-78166 Donaueschingen
Fon [phone] | Fax [phone] | [e-mail] | bb-sensors.com
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