ATS 2140-M Series, Instruction Manual

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P (Proportional) Default value 1.000%/°F:
The Proportional term (P) is in control during ramp to setpoint.
The Integral term (I) is enabled when the temperature reaches the difference between the setpoint and
Integral Enabled value, which is normally set at 25°F and should not be changed. To experiment with
furnace tuning:
1. Set the I term to zero and raise the P term until there is an oscillation of temperature. Reduce the
P term until oscillation disappears. This is the optimal value for the P term.
2. Increase the I term until the transition from ramp to steady state setpoint value is a smooth,
continuous curve without overshoot. This should occur within a reasonable time. If overshoot
exists, reduce the I term. If the transition time is excessive, increase the I term.
NOTE: It should not be necessary to change the remainder of the default values. Consult ATS at
+1-724-283-1212 if satisfactory temperature is not achieved.
I (Integral) Default value 0.030%/°F:
The I term is enabled during the latter part of the ramp function.
D (Derivative) Default value 0.01%/°F/M:
The derivative term will not need to be changed under normal
circumstances. Consult ATS at +1-724-283-1212 before changing this term.
Band Default 85°F:
This is the amount of “swing” allowed to the control parameters, meaning the
WinCCS control box varies the parameters during the control process as necessary. For normal creep
furnaces, this value will not need to be changed. Contact ATS for questions.
Integral Enabled Default 25°F:
This is the point on the ramp, in degrees, at which the control algorithm
enables the I term as the temperature approaches the setpoint value. In the case of the value set at 25°F
and the set point at 1000°F the I term will be enabled at 975°F. Enabling the I term prematurely results
in a longer time to reach the setpoint. Enabling it later may contribute to overshoot when the setpoint is
reached. It is seldom necessary to change this value.
Temperature Gain Default 1.00:
This gain term is not normally changed.
Maximum Power: This is normally set at 100%, which allows the control system to make use of the full
potential of the furnace. If full power is not needed from the furnace, set this default to a lesser value.
The control system will limit the power applied to that value.
Ramp Cutback Factor:
As the setpoint approaches, furnace power is automatically cut back from the
transition between the ramp and the steady state. This avoids overshooting and creates a steady,
continuous curve. The value of this cutback is typically set at 2.50 for a creep furnace.