Configuration 
3/07  UDC3500 Universal Digital Controller Product Manual  99 
3.13 Logic Gates Set Up Group 
Introduction 
This Set Up Group is provided only as part of the Math Options package. 
This group deals with various Logic Gates that are available for use in the controller. Up 
to five different gates can be configured. 
 
ATTENTION 
If the controller is configured to use the same relay for more than one function, then the 
following priority is used to determine how the relay functions: Control Outputs take 
precedence over Alarms, which in turn take precedence over Time/Events, which in turn 
take precedence over Logic Gate Outputs. For example, if you select the Loop 2 Output 
Algorithm as Time Simplex (which uses Relay 3), enable Alarm 3 (which also uses 
Relay 3) and configure a Logic Gate to use Relay 3, then the instrument will use Relay 
#3 to perform the Time Simplex output and ignore the Alarm and Logic Gate functions. 
Logic Gates are processed in numerical order.  For example, if Logic Gate 2 and Logic 
Gate 4 are configured in a contradictory manner, then Logic Gate 2 will take precedence 
and Logic Gate 4 will be ignored. 
Logic Gate Outputs configured for Relays will light an annunciator when active. 
Outputs for Relay 1 through Relay 4 will light annunciators OUT 1 through 4. Logic 
Gate Outputs for Relay 5 will light annunciator ALM 1. 
Function Prompts 
Table 3-13 LOGIC Group Function Prompts 
Function Prompt  
Lower Display 
Selections or  
Range of Setting  
Upper Display 
Parameter  
Definition 
LOG GATE 
 
 
DISABLE 
ENABLE 
LOGIC GATES—This feature is available only with 
controllers that have the math option. 
DISABLE—Disables Logic Gates Functions. 
ENABLE—Enables Logic Gates Function. 
 ATTENTION   For each Logic Gate, make a 
selection for: 
 Gate Type  GATEnTYP  
  Input A Source    GATEnINA 
  Input B Source    GATEnINB 
 Output Use  GATEnOUT 
    where n = 1, 2, 3, 4 or 5