How to autotune a loop, Setting up alarms, Failed sensor alarms – Watlow CPC400 User Manual
Page 77: Setting up alarms 63
CPC400 Series User’s Guide
Chapter 3: Operation and Setup
Doc. 0600-2900-2000
Watlow Anafaze
63
•
Heat power limit (if the heat output is used and 100%
power is not safe)
•
Cool power limit (if the cool output is used and 100%
power is not safe)
How to Autotune a Loop
1.
Go to the loop display (see Loop Display on page 50)
and press
p
to choose the loop to tune.
2.
Enter the desired set point or one that is in the middle
of the expected range of set points that you want to
tune for. (See page 54.)
3.
Set the control mode to tune. (See page 55.)
After the control mode on the loop display has switched to
adpt and stopped flashing, the PID parameters should be
close enough to provide good control. As long as the loop is
in the adaptive control mode, TRU-TUNE+™ continuously
tunes to provide the best possible PID control for the pro-
cess.
WARNING!
During autotuning, the controller sets the output
to 100 percent and attempts to drive the process
variable toward set point. Enter a set point and
heat and cool power limits that are within the safe
operating limits of your system.
Setting Up Alarms
The CPC400 has three main types of alarms:
•
Failed sensor alarms
•
Process alarms
•
System alarms
Failed Sensor Alarms
Failed sensor alarms alert you if one of the following condi-
tions occurs:
•
Thermocouple open
•
Thermocouple shorted (must be enabled)
•
Thermocouple reversed (enabled by default)
•
RTD open positive input or open negative input
•
RTD short between the positive and negative inputs