Emerson Tescom ER5000 Series, User Manual, Page: 151 / 248

ER5000 —
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The ERTune™ Program: Basic Features
The Integral Limits Controllers
These three controllers allow you to set a higher Integral term
while minimizing detrimental effects such as windup.
Maximum
This controller sets the limit for positive errors (setpoint minus
feedback is positive) that can accumulate for the Integral term
during error correction, typically after a change from a low to a
high setpoint. The Integral will stop adding positive value when it
reaches the level set by this limit, regardless of feedback.
Minimum
This controller sets the limit for negative errors (setpoint minus
feedback is negative) that can accumulate for the Integral term
during error correction, typically after a change from a high to
a low setpoint. The Integral will stop subtracting negative value
when it reaches the level set by this limit, regardless of feedback.
Deadband
This controller sets a range around the setpoint where the Integral
term will not respond to error.
The deadband range is measured as a percentage of the full
range of the feedback. For example, a setting of one percent (1%)
creates a deadband range from one percent above (+1%) to one
percent below (-1%) the setpoint.
The Deadband controller prevents system noise or a series of
small transient errors, from accumulating in the Integral term
to the point that the ER5000 is activated. In some applications,
accumulation of these errors can cause the ER5000 to be in a
perpetual state of activation.