Monitoring and Operating the Controller 
234  UDC3500 Universal Digital Controller Product Manual  3/07 
4.19 Monitoring Two Loops of Control 
Introduction 
Monitoring two individual loops of control or internal Cascade is similar as for a single 
loop with the following additions.  
 
Table 4-24  Digital Display Indication—Two Loops 
Indicator  Loop Indication  Definition 
none 
(two-loop) 
I 
(cascade) 
Loop 1  •  Upper display shows the Process Variable (PV) for Loop 1 
•  Lower display shows the Loop 1 parameters and the PV and 
Output for Loop 2  
•  Controller setpoint annunciators show the setpoint currently 
being used for Loop 1 
L” 
Loop 2  •  Upper display shows the Process Variable (PV) for Loop 2 
•  Lower display shows the Loop 2 parameters and the PV and 
Output for Loop 1 
•  Controller setpoint annunciators show the setpoint currently 
being used for Loop 2 
 
Loop Display 
Display of Loop 1 or Loop 2 (if configured) is selected by toggling the Func-Loop1/2 key. 
Viewing each Loop’s Process Variable 
Regardless of which loop is being displayed, 1 or 2, the process variable of the non-
displayed loop can be shown in the lower display by repeated presses of the Lower 
Display
 key until 1PVXXXX or 2PVXXXX is displayed. 
Internal Cascade Indication 
When internal Cascade has been configured, an “I” will appear on the left side of the 
upper display as long as Loop 1 is operating in the remote setpoint mode. Hold in the  
SP Select key until RSP appears in the lower display then release the key to select remote 
setpoint. 
Switching between automatic and manual mode on either loop will not affect the internal 
Cascade indication.