Alternate pid setup – Super Systems 9205 Series User Manual

Page 58

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Series 9205 Operations Manual Rev A

57

clicking on each option. Pressing OK will save the point. Note that all 32 points do not need to be entered;

however, the more points that are entered, the more precise the calculated value will be. Any values that

are not entered should be set to values beyond (above or below) the ranges entered.

The Return button will return the user to the menu screen.

Alternate PID Setup


IMPORTANT!

PID Auto Switching must be enabled in the PID Loop Setup menu before Alternate PID Setup settings will

be applied. This applies only to the Loop 1 – Loop 3 Set1-Set 3 menu options. All other menu options are for

recipe Opcode PID control.

The Alternate PID Setup menu option allows for up to

16 sets of PID values to be used on the first loop via the

programmer. This is frequently used if a different PID

would be more suitable once a furnace reaches a

certain temperature.

There is a choice of PID 1 – 16, and Loop 1 Set 1 -3,

Loop 2 Set 1 – 3, and Loop 3 Set 1 – 3.

Prop Band (0 for On/Off)

Proportional Band determines the response to the

current error. The Proportional Band is the percent of

the range of the process variable that will produce

100% output and is the inverse of the proportional gain.

A low Proportional Band value results in a larger change in output for a given error. Conversely, a high

Proportional Band value results in a smaller change in output for a given error. If the Proportional Band is

too small, control may oscillate or be otherwise unstable. If the Proportional Band is too large the control

action may be too sluggish in response to changes within the system. Note: If the Proportional Band is set

to 0.0, only on/off control is performed. The range is –1.0 to 999.0.

Reset

Reset determines the influence of past errors. The Reset, or integral action (expressed in repeats per

minute), sums the error between the process variable and setpoint over time and adds this accumulated

output to the proportional output. A “proportional only” controller generally operates with steady-state

error because some error is required to produce control output. The goal of integral action is to drive the

steady-state error to zero and eliminate this droop. The range is 0.00 through 10.00.

Rate
Rate adjusts the response to future errors.

The Rate, or derivative action (expressed in minutes), is used to

predict system behavior and has a dampening effect. The more the controller tries to change the process

variable the harder the derivative will work to counter that effort. This dampening effect can be valuable in

reducing overshoot but is most often useful when trying to improve control on systems with significant and

predicable lag.

The range is 0.00 through 10.00. NOTE: The rate is not typically used for carbon control.

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