7
Controller Operation
This chapter discusses in detail how to operate the temperature controller using
the front control panel. Using the front panel key switches and LED display the
user may monitor the process temperature, set the temperature set-point in de-
grees C or F, monitor the heater output power, adjust the controller proportional
band, and program the probe calibration parameters, operating parameters, and
serial interface parameters. Operation of the functions are shown in the
flowchart summarized in Figure 5.
7.1
Process temperature
The digital LED display on the front panel allows direct viewing of the process
temperature. This temperature value is what is normally shown on the display.
The units, C or F, of the temperature value are displayed at the right. For
example,
25.00 C
Process temperature in degrees Celsius
The temperature display function may be accessed from any other function by
pressing the “EXIT” button.
7.2
Temperature Set-point
The temperature can be set to any value within the range as given in the specifi-
cations with a high degree of resolution. The temperature range of the particu-
lar fluid used in a bath must be known by the operator and the bath should only
be operated well below the upper temperature limit of the liquid. In addition,
the high level set-point should also be set below the upper limit of the fluid.
Setting the temperature involves two steps: (1) select the set-point memory, (2)
adjust the set-point value
7.2.1
Programmable Set-points
The controller stores 8 set-point temperatures in memory. The set-points can be
quickly recalled to conveniently set the system to a previously programmed
temperature.
To set the temperature one must first select the set-point memory. This function
is accessed from the temperature display function by pressing “SET”. The
number of the set-point memory currently being used is shown at the left on the
display followed by the current set-point value.
25.00 C
Process temperature in degrees Celsius
S
Access set-point memory
23
7 Controller Operation
Process temperature
