Marathon Monitors Inc.
AACC 2000 Carbon Nov. 1, 1997
26
Basic operation
Switch on the power to the controller. It runs through a self-test sequence for about three
seconds and then shows the process value, in the upper readout and the setpoint, in the
lower readout. This is called the Home display.
Process Value (PV)
Setpoint
Figure 2-4 Home display
You can adjust the setpoint by pressing the or buttons. Two seconds after
releasing either button, the display blinks to show that the controller has accepted the
new value.
OP1 will light whenever output 1 is ON. This is normally the heating output when used
as a temperature controller.
OP2 will light whenever output 2 is ON. This is normally the cooling output when used
as a temperature controller.
Note: You can get back to this display at any time by pressing and together.
Alternatively, you will always be returned to this display if no button is pressed for 45
seconds, or whenever the power is turned on.
Alarms
If the controller detects an alarm condition, it flashes an alarm message in the Home
display. For a list of all the alarm messages, their meaning and what to do about them,
see Alarms at the end of this chapter.