Honeywell VRX180 - Manual (Page 250)

Online Operation Using Menus
Video Recorder – User Manual 236
Table 7-9 Tune Loop Prompts (continued)
Prompt Range/Selections Definition
RESET #1 0.005-99.99 repeats/minute Determines the period of time for a repeat of the proportional
gain output. Enter a starting value at initial configuration. The
value may be altered Online for final loop tuning. For loops
with dual tuning, Reset 1 is the time for the first set of tuning
parameters. Reset 2 is for the second set. (Variable Reset1
is available by programming a constant's Destination with
RS. See Program Constants, Section 4.16.)
A value of OFF may be entered to allow proportional-only
control. When turned off, the manual reset value determines
the loop output at setpoint. Bumpless manual to automatic
transfer is canceled when proportional only control is
selected.
RATE #1 0.02-10.00 minutes Modifies the loop output based on the rate of change of the
process variable. The output is modified by a value that
assumes the rate of change of the process variable will
continue for the time period specified. Enter a starting value
or OFF at the time of configuration. The value may be altered
Online for final loop tuning. For loops with dual tuning, Rate 1
is the rate for the first set of tuning parameters. Rate 2 is for
the second set. (Variable Rate1 is available by programming
a constant's Destination with RT. Program Constants,
Section 4.16.)
PROP. BAND #2 See GAIN #1
RESET #2 See RESET #1
RATE #2 See RATE #1
MANUAL RESET -100 to +100 This feature functions only when OFF is configured for the
loop’s RESET parameter. Enter a value equal to the desired
loop output when the process variable is at setpoint. This
allows correction of output to account for load changes to
bring the process variable up to setpoint.
SUPPRESS
OVERSHOOT
YES, NO This parameter set to YES limits overshoot of the Setpoint
(SP) by the Process Variable (PV) after a disturbance in the
process such as a load or SP change. Through fuzzy logic,
the working SP of the control loop is dynamically modified by
the control algorithm to reduce or eliminate overshoot.
PRETUNE Pretune calculates optimum values for a loop's Proportional
Band/Gain, Reset and Rate by analyzing the reaction of the
loop to a "step change" in setpoint or output. After these
new tuning values have been calculated you have the option
of applying (installing) or not applying them to a preselected
tune set of the loop. You can pretune a loop while another
loop is pretuning.
See Pretune Loop on page 238.
SET TIMEBASE 5 MIN, 15 MIN, 30 MIN,
1 HR, 2 HR, 4 HR Enter the timebase for the time axis of the tuning trend
display.