Installation manual

Introduction
900M050U00  Athena Controls, Inc. 1-5
1.3 Modes of Operation
1.3.1 Control Modes
Unless both standard outputs are set to offoff or ALRALR (alarm), the 1ZC, 16C, 18C, and 25C
controllers support several modes of operation for control, as well as a special mode
used to tune the unit automatically for PID control.
2
The table below summarizes the control modes and shows the display used to select
each. Instructions for using the keypad to display and change the mode are in 2.4. The
operational display for each mode is in 2.2.1.
Control
Mode
Selection
Display
Description
normal
CtrLCtrL
nornor
When the controller is in normal mode, the outputs are based on
the controller’s calculations in accordance with the configured
control strategy, dependent on the input received.
standby
CtrLCtrL
StbYStbY
When the controller is placed in standby mode, the controller does
not calculate any outputs until the controller is taken out of
standby. While in standby, the control outputs are in their
unactivated state (open or closed, depending on the type of relay).
Analog outputs are set to their minimums in standby mode.
manual
(fixed output
percentage)
CtrLCtrL
FOPFOP
When the controller is placed in manual mode, then, regardless of
the configured control strategy and the input received, the outputs
used are the fixed percentages specified by the operator using the
percent 1 and percent 2 values. See 2.4.5 for the procedure.
Autotune
CtrLCtrL
AtunAtun
When Autotune is selected, the PID outputs are put under the
control of the Autotune algorithm, and dependent on the input
received. Autotune is not always available. The controller and
the process must be prepared before the controller is placed in
Autotune mode. See 16.2 for details.
ramp/soak
start
CtrLCtrL
r.Sr.S
If the controller’s ramp/soak parameters have been used to
enable the controller to execute a single-setpoint ramp or a multi-
step recipe, then this choice is available. When ramp/soak start is
selected from the list of available modes, the single-setpoint ramp
or multi-step ramp will be executed, based on the values stored in
the controllers ramp/soak parameters. The outputs will be
calculated by the controller to achieve the recipe setpoint. The
recipe setpoint will be manipulated by the controller in accordance
with the ramp and soak segments configured using the controller’s
ramp/soak parameters. See Section 11 for details.
ramp/soak
hold
CtrLCtrL
rS.rS. HH
If the controller is running a multi-step recipe based on the
ramp/soak parameter values (that is, if r.Sr.S is alternating with the
display of the PV), then the ramp/soak hold choice is available on
the list of modes. When this choice is selected, the setpoint is
held at the level reached when the recipe was put on hold.
resume
ramp/soak
CtrLCtrL
rS.rS. rr
If a recipe is currently being held (that is, if rS.rS. HH is alternating
with the display of the PV), then the resume ramp/soak recipe
choice is available on the list of modes. When this choice is
selected, the controller resumes execution of the recipe.
2
When both standard outputs are off or used for alarm annunciation, the instrument functions as a non-
controlling indicator. When the outputs are not used for control, the operating modes are not applicable
(they are all related to the behavior of outputs), so no mode is displayed when you press the key.