122-28176 Parallax Inc, 122-28176 Datasheet - Page 302

• Manufacturer Part Number: 122-28176
• Description: GUIDE STUDENT PROCESS CONTROL
• Manufacturer: Parallax Inc

Specifications of 122-28176

• Accessory Type: Manual
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Propeller Education (PE) Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

Page 292 · Process Control
Figure 8-17 Proportional - Integral System Response
Looking at our results in Figure 8-17, at Time 1 (T1 marked on plot), the system is fairly
stable at 96 °F on only 50% bias. At this point, the setpoint is changed to 105 °F, K
is
P
set to 0.1, and the error causes temperature to rise.
At T2, the system has stabilized with proportional control at a temperature of 101.5 °F
(pure coincidence). From the lower plot, we can see that the steady-state error is 9.1%
for proportional drive. Integral control is introduced with a K
of 0.001.
I
At T3, the system has almost reached the setpoint. Note that proportional drive is nearly
0 (1.7%) and integral drive is 19.2, for a total drive of 70.9. Because integral plus bias