Most Programmable logic Controllers (PLCs) are designed to operate from a 24 VDC power supply. This industry standard ensures that the PLC is compatible with the ecosystem of components found in a typical control panel. However, there are times when a 12 VDC PLC is more convenient such as when an automotive or marine 12 VDC power system is used.
Digikey offers a variety of PLCs that operate at 12 VDC. A representative example is shown in Figure 1. This Siemens LOGO! model 6ED10521MD080BA2 features an integral display and pushbutton interface. It may be used on 12 or 24 VDC systems.
This article is part of the DigiKey Field Guide for Industrial Automation
Location: Select It → PLCs
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Author: Aaron Dahlen | MSEE | Senior Applications Engineer, DigiKey
Last update: 10 Mar 2026
Figure 1: This Siemens LOGO! PLC will operate in a 12 VDC system.
Tech Tip: The supply voltage is generally associated with input voltage. For example, a PLC with a 24 VDC will generally use 24 VDC sensors. Deviation from the 24 VDC industry standard will limit the variety and number of compatible field devices.
How can I find 24 VDC PLCs?
The power supply specification is included in DigiKey’s parametric search engine as shown in Figure 2. Like other searches, simply select desired power supply voltage.
Figure 2: The PLC supply voltage specification is included in DigiKey’s parametric search engine.
Best wishes,
APDahlen
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About This Author
Aaron Dahlen, LCDR USCG (Ret.), is a Senior Applications Engineer at DigiKey in Thief River Falls. His background in electronics and industrial automation was shaped by a 27-year military career as both technician and engineer, followed by over a decade of teaching.
Dahlen holds an MSEE from Minnesota State University, Mankato. He has taught in an ABET-accredited electrical engineering program, served as coordinator of an electronic engineering technology program, and instructed military technicians in component-level repair.
Today, he has returned to his home in northern Minnesota, completing a decades-long journey that began with a search for capacitors. Read his story here.