Rockwell Automation 900-TC32 Digital Temperature Controllers, Series B - Manual (Page 253)

Publication 900-UM007D-EN-E - January 2011
Parameter Functions & Definitions 5-25
AT Execute/Cancel
Conditions of Use: The Bulletin 900-TC8, 900-TC16, or 900-TC32 must be
in operation (RUN), and the control method must be 2-PID control.
Function: This parameter allows you to initiate (turn ON) the controller’s AT
(auto-tuning) function.
When you initiate auto-tuning, the optimum PID parameters (Proportional
Band, Integral Time, and Derivative Time) for the current set point during
program execution are automatically set by the controller forcibly changing the
manipulated variable to calculate the characteristics of the control target.
Table 5.AA
• Both 100% AT and 40% AT are supported for AT.
• Only 100% AT can be executed for heating and cooling control.
• For 900-TC8 and 900-TC16: This parameter will not be displayed
when either 100% or 40% AT execute/cancel is set to be executed using
an event input.
• This parameter is normally off . Press the U Key and select at-2 or
at-1
to execute AT. AT cannot be executed when control is stopped or
during ON/OFF control.
• When AT execution ends, the parameter setting automatically returns to
off
.
Related Parameters
• Proportional Band, Integral Time, Derivative Time (Adjustment
function group, page 5-35)
• PID ON/OFF (Initial Setting function group, page 5-55)
Configurable Range Default
OFF: AT Cancel
OFF AT-2: 100% AT Execute
AT-1: 40% AT Execute
at