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 traditional features of PLCs, DCSs, PCs, and RTUs.

Which features will you need for your application?

Feature PCs 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 x
Remote monitoring & control, SCADA   x x   x
Motion control x       x
Multi-domain capabilities (One controller performs logic, process control, discrete control, motion control, monitoring, and data acquisition.) x       x
Distributed control functions to reduce load on central controller (examples: 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       x
Efficient processing and I/O scanning (PACs scan only when logic requires it, thus reducing data polling and network traffic.) x     x x
Data-intensive applications such as recipe or batch processes; recipe switching x x   x x
Floating-point math x 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   x
Open languages and standard protocols x x     x
Open, standard network interfaces x       x
Easy support for multiple vendors' hardware & software x       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