Honeywell VRX180 user manual Loop Menu Items, Loop Prompts

Programming Function Blocks and Features

Loop Menu Items

Table 4-10 alphabetically describes every loop menu item. See Table 4-2 for additional prompts.

Table 4-10 Loop Prompts

Prompt	Range/Selections	Definition
APPROACH HIGH	Enter a value 0.1 to 100 or	This function affects the process variable approach to set
	OFF.	point when the process variable value is less than the set
		point value. The value entered is the percent of span
		deviation from set point at which a recalculation of the
		loop integral value will occur. Enter a starting value equal
		to the proportional band value (1/gain value) x 100 if Gain
		is used, or OFF at initial configuration. The value may be
		altered Online for final loop tuning. This function is useful
		for batch startup from a "cold" condition to control
		excessive overshoot when set point is reached.
APPROACH LOW	Enter a value 0.1 to 100 or	Affects the process variable approach to set point when
	OFF.	the process variable value is greater than the set point
		value.
AUTO/MAN SELECT	OFF, discrete parameter, 0, 1	This parameter takes the place of the Auto/Man button
		when the DISCR VS KEY SEL discrete is ON (1).
		AUTO/MAN SELECT = ON(1) = Manual mode
		AUTO/MAN SELECT = OFF (0) = Automatic mode
		When DISCR VS KEY SEL is OFF(0), AUTO/MAN SEL
		has no effect.
CHG ACTION INPUT	OFF, discrete parameter, 0, 1	Change Action Input. Selects the opposite control action
		from that selected for the control action (see CONTROL
		ACTION). Control action is opposite when the discrete
		value is ON or "1".
CONTROL ACTION	Reverse (REV) or Direct (DIR)	When Reverse Acting Control is selected, the loop output
	Acting Control.	will increase as the process variable becomes less than
		set point, and will decrease as it becomes greater than
		the set point. When Direct Acting Control is selected, the
		output action is opposite.
DISCR VS KEY SEL	OFF, discrete parameter, 0, 1	Discrete vs. Keyboard select. When this discrete is ON
		(1), the Auto/Man and Set point buttons are disabled; their
		functioning is transferred to the AUTO/MAN SELECT and
		SETPOINT SELECT discretes. See AUTO/MAN SELECT
		and SETPOINT SELECT. Status changes made by
		AUTO/MAN SELECT and SETPOINT SELECT will remain
		when DISCR VS KEY SEL is OFF (0).
DUAL TUNING SEL	OFF, discrete parameter, 0, 1	When ON(1), selects the second set of tuning constants
		(#2). A bumpless transfer (integral term adjusted)
		calculation will be made on transition.

94 Video Recorder – User Manual