54
WATLOW Series 942 User's Manual
Appendix
NOTE:
Calibration values
are not retained
unless you are in the
RUN mode. Do not
enter the RUN mode
until you are at the
correct input
parameters.
Appendix 3
Before attempting to calibrate, make sure you have the
proper equipment called for in each procedure.
Entering the Calibration Menu
In the Calibration Menu, various input signals must be supplied in order for the
control to go through its auto calibration. The calibration menu can only be
entered from the LOC parameter in the Setup menu. Press the UP/DOWN
keys simultaneously for 3 seconds (
±
1 second). The CAL parameter appears
in the lower display with "no" in the upper display.
Any inadvertent change in the displayed data, when pressing the UP/DOWN
keys, is ignored. Calibration values are not retained unless you are in the RUN
mode. Press the UP/DOWN keys to change the upper display to “YES.” Press
the MODE key to enter the calibration sequence.
Upon entering the calibration menu, the top display window indicates CAL. The
upper display continues to indicate CAL (with the exception of calibration of the
process outputs) while the operator walks through the entire calibration param-
eter list. While calibrating a process output, the upper display contains a
numeric value to be slewed up or down until the output value is correct. The
control uses the lower display to prompt the user as to what the input should be
The rSt parameter restores the factory calibration values to the Series 942.
If you calibrate your control incorrectly, you have the option to default to the
original values. Once you leave the CAL menu, the values are entered.
The dFL parameter allows you to select either U.S. parameters which include
displaying the proportional band in degrees or units, rate, reset, and
°
F. Or you
can select SI (System International); those parameters displayed are propor-
tional band in % of span, integral, derivative, and
°
C.
Once the information has been properly established and maintained for 5 to 10
seconds, the MODE key can be used to display the next parameter. After the
final input is established, press the MODE key to return the unit to the configura-
tion menu at the top of the parameter list.
Calibration
Figure 45 -
Entering the
Calibration Menu.
NOTE:
While in the Calibra-
tion Menu, all
outputs are OFF,
except the process
output.
WARNING:
Improper calibration
will affect the
accuracy of your
control. A factory
restore (rst) feature
is provided at the
end of the Calibra-
tion menu.
!
