A PLC system integrator owns the full control system as one engineered solution, while a controls contractor typically installs or wires hardware to a provided design. Integration covers logic, device coordination, communication and commissioning, not just the physical build.
Contrasting the roles of system integrators and controls contractors:
- Integrator responsibilities: Responsible for the design and programming of control logic, ensuring the entire system functions according to the intended machine sequence.
- Contractor responsibilities: Generally focused on the physical aspects, such as panel construction, wiring and installation based on external specifications.
- Ownership of the system: An integrator manages the coordination between the PLC, HMI, drives and network to ensure they operate as a unified machine.
- Integrator role: Designs and programs the control logic, then proves the whole system works against the machine sequence.
- Contractor role: Often handles panel build, wiring and installation to a specification someone else created.
- System ownership: An integrator coordinates the PLC, drives, HMI and network so the parts function as one machine.
Part of that difference is who carries certification and build quality on the panel itself. For an example of where those standards matter, read Adgo on the difference between UL 508A and UL 698A.
