Honeywell UDC 3300 manual Introduction Algorithm group prompts

4.6Algorithm Data Set Up Group

Introduction

Algorithm group prompts

This data deals with various algorithms residing in the controller:

•Control algorithms,

•Input Math algorithms,

•selecting the 1 or 2 PID Loops,

•Output Override,

•2 Eight Segment Characterizers,

•the Timer function,

•Totalizer function, and

•Gain Scheduling.

ATTENTION Math option (two algorithms, two characterizers, totalizer) and Two Loops of Control are only available on Expanded Model DC330E.

Table 4-5 lists all the function prompts in the Algorithm Set Up group and their definitions.

Table 4-5 Algorithm Group Definitions

Lower Display

Prompt

CONT ALG

Upper Display

Range of Setting

or Selection

ON-OFF

Parameter

Definition

The CONTROL ALGORITHM lets you select the type of control that is best for your process.

ON/OFF is the simplest control type. The output can be either ON (100 %) or OFF (0 %). The Process Variable (PV) is compared with the setpoint (SP) to determine the sign of the error (ERROR = PV–SP). The ON/OFF algorithm operates on the sign of the error signal.

In Direct Acting Control, when the error signal is positive, the output is 100 %; and when the error signal is negative, the output is 0 %. If the control action is reverse, the opposite is true. An adjustable overlap (Hysteresis Band) is provided between the on and off states.

Other prompts affected: OUT HYST

DUPLEX ON/OFF is an extension of this algorithm when the output is configured for Duplex. It allows the operation of a second ON/OFF output. There is a deadband between the operating ranges of the two inputs and an adjustable overlap (hysteresis) of the on and off states of each output. Both Deadband and Hysteresis are separately adjustable. With no relay action the controller will read 50 %.

Other prompts affected: OUT HYST and DEADBAND

92 UDC 3300 Process Controller Product Manual 4/00