Watlow Controls Series 998, User Manual

Page: 28 / 126

Keys and Displays, Chapter 3 3.2
WATLOW Series 998 User’s Manual
Display Loop
Display Key and Loop
On power up, the Series 998 displays the channel A set point value in the
lower display and the channel A process value in the upper display and
the CH A (channel A) indicator light is on. Press the Display key once to
view the channel B set point and process values (CH B will be lit). Press
the Display key once again and channel A process value is displayed in
the upper display and channel B process value is displayed in the lower
display. At this point, both CH A and CH B will be lit. Press the Display
key again to display units.
Any point in any menu, if no key is pressed for one minute the display
returns to displaying the channel A process and set point.
Display Loop Parameters
Channel A Process and Set Point: The channel A process value is shown
in the upper display. The set point is shown in the lower display, it sets
the operating set point for the channel A control outputs. If channel A is
in manual mode the set point is in percent output.
Range: [`rL1] to [`rH1] in auto mode
[-100]
% to
[`100]
% in manual mode (heat/cool)
[```0] % to [`100] % in manual mode (heat only)
[-100]
% to
[```0]
% in manual mode (cool only)
Default: depends on input 1 range and type
Channel B Process and Set Point: The channel B process value is
shown in the upper display. The set point is shown in the lower display, it
sets the operating set point for the channel B control outputs. If channel
B is in manual mode the set point is in percent output.
Range: [`rL2] to [`rH2] in auto mode
[-100]
% to
[`100]
% in manual mode (heat/cool)
[```0] % to [`100] % in manual mode (heat only)
[-100] % to [```0] % in manual mode (cool only)
Default: depends on input 2 range and type
Process A and Process B: The channel A process value is displayed in
the upper display with channel B process value displayed in the lower
display.
Range: depends on input types
Default: none
Units: Shows the units associated with the temperature value. This para-
meter shows what the
[`C-F]
(Global Menu) is set to.
Range:
[``°F]
or
[``°C]
Default: none
Hidden if: input 1 and input 2 are process inputs
Figure 3.2 -
The Display Loop.
[`75]
[100]
[`80]
[125]
[`75]
[`80]
[```]
[`°F]
Channel B
Process
Channel B
Set Point
Channel A
Process
Channel B
Process
Process
Units
Channel A
Process
Channel A
Set Point
Display Loop
∂
∂
∂
∂
NOTE:
Lower display alter-
nately flashes
[`rP`] and lower
display value when
ramping is in
process.