User manual

Copyright © 2005, ZMD AG, 2005-05-17 5/8
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior
written consent of the copyright owner. The Information furnished in this publication is preliminary and subject to changes without notice.
ZMD31050
Advanced Differential Sensor Signal Conditioner
Application Note PRELIMINARY
These values should be 0.5/4.5V. In most cases this wouldn’t be so and is caused by tolerances of all
components/elements at the PCBs – calibration is necessary. This is the next step.
• Open “Sensor-Calibration” dialogue (last picture)
• A two point calibration
(poti top & down) should be
done.
 “Calibration Mode” is
linear, no temperature
behaviour. Adjust this like
displayed in screenshot.
Tooltips in software give
you additional help for use.
 “Targets” are the output
aims for calibration. In
example output voltage
should be 0.5/4.5V for
minimum/maximum input
signal. All targets are
inputted proportionally to
VDDA, complete calibration
is done proportionally to
VDDA. For VDDA=5V is a
required output voltage of 0.5/4.5V => target is 10/90%. This has to be inputted in target frame for
minimum and maximum.
 “Acquire Raw Data” frame is used to collect data of all
needed measurement points for calibration. In minimum 2
input fields and acquire buttons are enabled depending on
selected “Calibration Mode”.
• Adjust SR poti to top end and press “P1M” button.
The current analogue input signal is gained and AD-converted
now, the result is displayed in the input field beside the button.
• Adjust SR poti to down end and press “P2M” button.
Both required data points for calibration are acquired now,
calculation of calibration coefficients can be done now.
• Press “calcCoeff” button in “Sensor Calibration” dialogue.
Software messages success of coefficients calculation.
Founded calibration coefficients are copied to RAM register
block. To verify this open “RAM-Register” dialogue by
pressing the “RAM_EEP” icon in icon list of software.
• Press “Write+Cyc_RAM” button in main window now.
Calibration results are transferred to ZMD31050 and activated
Sensor-Calibration: Target input fields and acquire raw data buttons
Calibration results
RAM Register dialogue