122-28176 Parallax Inc, 122-28176 Datasheet - Page 11

• 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

Chapter 1: Process Control and Flowcharts
BEFORE YOU START
To perform the experiments in this text, you will need to have your Board of Education
connected to your computer, the BASIC Stamp Editor software installed, and to have
verified the communication between your computer and your BASIC Stamp.
detailed instructions, see What’s a Microcontroller? - a free download from
www.parallax.com. You will also need the parts contained in the Process Control Parts
Kit. For a full listing of system, software, and hardware requirements, see Appendix B.
WHAT IS PROCESS CONTROL?
Process control refers to the control of one or more system parameters, such as
temperature, flow rate or position. While most systems are a continual process, such as
maintaining a temperature, other processes may be a sequence of actions, for example,
the assembly of a product.
Control systems can be very simple or very complex. Figure 1-1 is a block diagram of a
simple continuous control system. For control of the process, an input (such as a setpoint
control or switch) is required into the controller. Based on the input, the controller will
drive an actuator to cause the desired effect on the process.
Examples of actuators are heaters for temperature, pumps for flow, and servos for
positioning.
Consider the example of a common car heating system. The driver adjusts a temperature
control to change the heat output of the vents. If the driver becomes too warm when
weather conditions change, the temperature control must be adjusted to return to a
comfortable temperature. This is a very simple system in that most automobiles do not
monitor the cabin with temperature sensors to automatically control the heat output of the
vents.
Controller
Input
Controller
Chapter 1: Process Control and Flowcharts · Page 1
Process
Actuator
Figure 1-1
Simple Process
Control Block
Diagram
For