PART V | LESSON 21: POWER AND NETWORKS MATERIAL HANDLING ACADEMY
DRIVING QUESTION What keeps the system powered, connected, and defended?
Left half: a 480-volt three-phase feed enters a control panel and steps down to a 24-volt DC control domain powering a PLC, an MDR zone, and a sensor. Right half: a PLC and a WCS on an EtherNet/IP segment and a safety PLC carrying CIP Safety over the same network, all on an OT network segmented from a business and IT network at a gold firewall boundary crossed by one controlled remote-access path.

Two voltage worlds on the left; one industrial network, segmented from the office, on the right.

Two Voltage Worlds

480V Three-Phase AC

Feeds the big motors, the sorter drive, and the panels.

24V DC Controls

Runs the PLC I/O, the MDR zones, the sensors from Lesson 19, and the safety devices from Lesson 20.

One Industrial Network

EtherNet/IP

Carries the standard control traffic between the PLC and the WCS and the device-level equipment at the machine.

CIP Safety

Carries the safety-rated messaging: e-stops, light curtains, and interlocks. Rides the same network, keeps its integrity.

DESIGN PRINCIPLE Know which voltage world it lives in.