Measurement Computing TempBook rev.3.0 - Manual (Page 18)

2-8 Installation, Configuration, and Calibration 11-16-00 TempBook User’s Manual
Connection Troubleshooting
If communications cannot be established with the TempBook or if trying to connect causes the system to
hang or crash, then you should:
•
Check that TempBook’s power LED is ON. If not ON, verify power connection between the
TempBook and the power source.
•
Make sure the LPT cable is firmly attached to the computer’s proper LPT port and to the TempBook
port labeled “TO COMPUTER”.
•
Check that the desired LPT port has the proper resource configurations. The base address and IRQ
level must be properly configured and recognized by the operating system. The parallel port must be
capable of generating interrupts for proper operation. (This information may be obtained in the
Device Manager in the Control Panel of the operating system). More information on this subject can
be found in the readmew.txt file in the current software release.
•
Check the BIOS settings for the LPT port. Make sure the BIOS LPT protocol settings are compatible
with the settings selected for the LPT port with the Control Panel applet.
•
Make sure the Daq Configuration Applet has been run and the proper LPT port and protocol have
been selected for the device. The Daq Configuration applet can be found in the Control Panel of the
operating system. The Test Hardware function in the control panel applet can be used to confirm
proper communication with the device.
Calibration of TempBook
The TempBook/66 is factory calibrated for gain and offset. After calibration, the unit is characterized for
gain and offset errors, and software correction constants are calculated. For users who wish to use these
constants within their own programs, see the Software Calibration and Zero Compensation chapter.
Calibration Constants File Installation
Each TempBook is shipped with a disk containing a calibration constants text file. The file is named
serial_no.cal where serial_no is the serial number of the TempBook for which the constants were generated.
The default calibration constants filename assumed by TempView is tempbook.cal.
The following command can be used to copy and rename the file if executed from the floppy disk drive.
COPY SERIAL_NO.CAL C:\TEMPBOOK\WIN\UTILS\TEMPBOOK.CAL
Hardware Calibration
Since the TempBook is factory characterized after calibration, user recalibration is not recommended.
However, one exception to this recommendation is the calibration of the TempBook's internal 5V reference.
This 5V reference is used to level-shift the amplified analog input signal for unipolar measurements.
Reference-voltage drift is not compensated for with zero compensation; and therefore, periodic
recalibration can improve unipolar measurement accuracy.
The following characteristics can be calibrated through potentiometer adjustments on the TempBook main
board:
•
5V Reference Voltage
•
Instrumentation Amplifier Offset
•
Level Shift Amplifier Offset
•
ADC Offset
•
ADC Span
The TempBook includes a simple calibration program that can be used to perform these adjustments. If the
user is only performing the reference voltage adjustment, then only a 4-1/2 digit DMM is required. If the
user is performing the full TempBook calibration, then an adjustable voltage calibrator is also required.
A Microsoft Windows program, TEMPCAL.EXE, is provided to perform calibration of the TempBook. To
use this program, install the TempBook Windows support and launch the TEMPCAL program; follow the
on-screen instructions.