In order for a PLC to control an automated machine or process, it must be given a set of instructions. These instructions, or user programs, tell the PLC what inputs to monitor, how to process the data, and how to respond to the inputs.
Learning Objectives
- Identify the four steps a PLC performs during operation
- Define the term input scan
- Define the term program scan
- Define the term output scan
- Identify the symbols representing normally open and normally closed contact relays
- Identify the two structures used for programming
Language: English