Watlow Series 988 - Manual (Page 104)

6.12 WATLOW Series 988 User’s Manual Factory Menus, Chapter 6
Factory-Diagnostic
Open Loop
Checks the control loop, consisting of the controller output, power
control, heater and sensor. With open loop enabled, the controller moni-
tors the output power level and checks for a change in the process input
value. If the output power is at maximum for a period of time equal to the
reset time and the process input has not changed by at least
±5°F, the
controller will switch to manual mode at 0% output power and [OPLP] will
be displayed in the lower display.
To clear this error, enter the Setup Menu and press the display key ∂.
To get back into auto mode, press the Auto/Man key å.
[OPLP] This prompt always appears.
Default
↓
[`OFF] [``on]
[OPLP] [OPLP]
[OPLP]