Monitoring and Operating the Controller 
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4.20  Operating Two Loops of Control 
Introduction 
Operation of two individual loops of control is identical to operating a single loop of 
control except that TUNING 2 group applies to Loop 2 only and four PID sets, 5 through 
8, are available. TUNING group applies to Loop 1 with PID sets 1 through 4 applicable. 
Operating modes and setpoint source 
The rules for Auto/Manual modes and changing setpoint sources are the same as single 
loop operation. 
Keyboard operation 
Note that the loop being displayed is the only loop affected by normal keyboard 
operation. However, either loop can be reconfigured when in the Set Up mode regardless 
of which is being displayed during normal operation. 
Accutune III 
Two independent loops or cascaded loops can be tuned at the same time, if so configured. 
Setpoint Ramp or SP Programming 
Either loop or both loops can be configured for a single setpoint ramp operation by 
enabling the desired loop or loops (see Section 3 – Configuration) 
An “H” or “R” will appear in the upper display when applicable, depending upon which 
loop is being displayed. 
Digital Inputs (remote mode switching) 
Digital Input 1 is dedicated to Loop 1 when two loops or Cascade control is configured. 
The other digital inputs may be configured to work on either loop. 
Output Override Hi/Lo select 
Output Override allows you to select the higher of Output 1 and Output 2 (Hi Select) or 
the lower of Output 1 and Output 2 (Lo Select) to appear at Output 1 terminals to drive 
the final control element. Refer to Section 5.12 for Override rules and block diagram. 
Override prompts appear under the Algorithm Set Up group, function prompt OUT 
OVRD.