Comparing PACs to Other Automation Technologies

It's easier to understand and evaluate a new technology if you can see how its capabilities compare with technologies you already know. This chart compares features of a PAC with those of PLCs, DCSs, and RTUs.

Which features will you need for your application?

Feature	PLCs	RTUs	DCSs	PACs
Industrially hardened hardware	x	x	x	x
Discrete control/sequential control	x	x		x
Process control (batch and continuous)	x		x	x
Remote monitoring & control, SCADA	x	x		x
Motion control				x
Multi-domain capabilities (One controller performs logic, process control, discrete control, motion control, monitoring, and data acquisition.)				x
Distributed control functions to reduce load on central controller (PID loop control, pulse generation, latching, events and alarms)			x	x
Critical local operations continue in the event of a communication failure			x	x
Multifunction (Meet complex requirements without add-ons or middleware.)				x
Multitasking				x
Efficient processing and I/O scanning (PACs are exception-based, scanning only when logic requires it, thus reducing data polling and network traffic.)			x	x
Data-intensive applications such as recipe or batch processes; recipe switching	x		x	x
Floating-point math	x		x	x
Compact, high-density system	x			x
Flexible, modular architecture (Use same hardware in small or large system; easily expand system with additional modules.)				x
Extensive communication options		x		x
Open languages and standard protocols	x			x
Open, standard network interfaces				x
Easy multi-vendor support				x
Integrated hardware and software			x	x
Integrated development environment for all applications (Discrete, analog, serial, motion, etc. Reduces programming effort/time.)				x
Common tagname database (No retyping or cross-reference lists.)	x			x
Long, plain-language tagnames				x

More information on PACs

What Is a PAC?

Thinking of buying a PAC? See Considerations for Choosing a PAC

Find out what software is used to program a PAC

Learn more about PACs in an interactive format

Read the white paper, Understanding Programmable Automation Controllers (PACs) in Industrial Automation

Do you need a standalone PAC or a rack-mounted PAC? See specifications for Opto 22's SNAP PAC programmable automation controllers