🔍 Key Concepts
• Look at how inputs and outputs are labeled in the PLC diagram.
• Think about whether switches, counters, and sensors are devices that send signals to the PLC or receive signals from it.
• Compare the roles of the processor module, power supply module, and the various I/O (input/output) modules.
💭 Think About
• On the illustration, which modules are physically connected to field devices like switches and sensors, and how are they labeled?
• Do switches and sensors normally control what the PLC does, or do they act on commands from the PLC—are they inputs or outputs?
• Which choice specifically mentions the types of signals (DC, AC, analog) that you would expect from sensors and counters going into the PLC?
✅ Before You Answer
• Verify which side of the PLC rack in the diagram is handling field inputs versus field outputs.
• Check that the component you choose is clearly marked as handling signals coming into the processor, not signals going out.
• Confirm that your choice includes the same types of signals shown next to the switches, counters, and sensors (e.g., DC, AC, analog).