Honeywell UDC 3300 manual Operating Two Loops of Control, Loop operation

5.15 Operating Two Loops of Control

Loop operation

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 two PID sets, 3 and 4, are available. TUNING group applies to Loop 1 with PID sets 1 and 2 applicable.

Operating modes and setpoint source

Keyboard operation

The rules for Auto/Manual modes and changing setpoint sources are the same as single loop 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

Setpoint ramp or SP programming

Digital inputs (remote mode switching)

Output override Hi/Lo select

Two independent loops or cascaded loops can be tuned at the same time, if configured.

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 when applicable, depending upon which loop is being displayed.

The RUN/HOLD operation is shown in Table 5-15 Procedure for Running a Setpoint Ramp.

Digital Input 2 is dedicated to Loop 2 and Digital Input 1 is dedicated to Loop 1 when two loops or Cascade control is configured.

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.

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