csmstr - Omega Engineering

CSSG – STRAIN GAGE INPUT PID MODULE PROGRAMMING
CRIMSON USER MANUAL - MODULAR CONTROLLER
Proportional Band is adjustable from 0.0% to 1000.0%, and should be set to a
value that provides the best response to a process disturbance while minimizing
overshoot. A Proportional Band of 0.0% forces the controller into On/Off
Control with its characteristic cycling at setpoint. The optimal value may be
established by invoking Auto-tune.
• The Integral Time is the time in seconds that it takes the integral action to equal
the proportional action, during a constant process error. As long as the error
exists, integral action is repeated each Integral Time. The higher the value, the
slower the response. The optimal value may be established by invoking autotune.
The Integral Time is adjustable from 0 to 6000.0 seconds.
• The Derivative Time is the seconds per repeat that the controller looks ahead at
the ramping error to see what the proportional contribution will be and it
matches that value every Derivative Time. As long as the ramping error exists,
the derivative contribution is repeated every derivative time. Increasing the value
helps to stabilize the response, but too high of a value, coupled with noisy signal
processes, may cause the output to fluctuate too greatly, yielding poor control.
Setting the time to zero disables derivative action. The optimal Derivative Time
may be established by invoking auto-tune. The value is adjustable from 0 to
600.0 seconds.
• The Power Filter is a time constant, entered in seconds, that dampens the
calculated output power. Increasing the value increases the dampening effect.
Generally, a Power Filter in the range of one-twentieth to one-fiftieth of the
controller’s integral time (or process time constant) is effective. Values longer
than these may cause controller instability due to the added lag effect.
THE POWER TAB
POWER TRANSFER
• The Output Offset value effectively shifts the zero output point of the module’s
output power calculation. This feature is most commonly used in proportionalonly
applications, to remove steady-state error.
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