Senior Automation Software PLC Engineer - Critical Infrastructure

Senior Automation Software PLC Engineer – Critical Infrastructure

As a master system integrator (MSI), Smart Tech Contracting excels in streamlining complex building automation system (BAS) and technology integrations, offering a comprehensive turnkey package that includes DDC, PLC, and SCADA solutions. We provide systems design, graphical standards development, central plant optimization (CPO), enterprise‑level energy and operational monitoring, and robust alarming solutions. Our expertise in hyperscale and colocation data center integrations ensures seamless, efficient operations vital in today’s data‑driven world.

Senior Automation Software PLC Engineer – Critical Infrastructure

Must relocate to or live in Atlanta, GA area

Smart Tech Contracting recognizes salary ranges from job boards do not necessarily reflect our pay ranges. In many instances we out‑compete those ranges for well‑qualified candidates.

The Senior Automation Software PLC Engineer – Critical Infrastructure owns the complete PLC software life‑cycle for hyperscale and colocation data‑center campuses ranging from 10MW to 200MW+. You will architect, program, and lead level 2/3/4/5 commissioning of high‑availability PLC solutions that integrate mechanical, electrical, and IT/OT subsystems—ensuring Tier III/IV reliability while meeting aggressive speed‑to‑market schedules. You will serve as the PLC subject‑matter expert (and secondary SME on SCADA development and integration) to ensure seamless hand‑offs, tag mapping, and site testing.

You will lead development of PLC logic, modular function blocks, state machines, and fault‑tolerant control strategies across multiple projects. You will coordinate closely with field electricians, startup & commissioning technicians, and the SCADA Engineer to validate end‑to‑end data flow, alarms, and historian points. You will provide on‑site SME support during Level 2‑through‑Level 5 Integrated Systems Testing (IST), troubleshooting complex field issues under live pressure.

You will implement robust code‑management, simulation, and cybersecurity practices aligned with ISA/IEC 62443 and owner standards. You will be self‑directed on day‑to‑day work and independently perform most responsibilities, lead teams and projects of complex scope, coordinate activities of other personnel, and assist in developing policies and procedures. You will communicate and operate in line with organizational goals and values, as well as departmental objectives.

• Design, program, and debug PLC logic for chilled‑water plants, HVAC, CRAH/CRACs, fan wall systems, and liquid cooling solutions
• Build reusable library objects and automated test harnesses; perform Factory Acceptance Testing (FAT) and Site Acceptance Testing (SAT)
• Execute Level 2 & 3 panel checkout and Level 4 functional testing; generate corrective patches during Level 5 IST

• Collaborate with SCADA Engineer to develop tag maps and naming conventions; configure BACnet/IP, Modbus
  
  TCP, OPC‑UA, and SNMP interfaces
• Support OT network validation (VLAN segmentation, redundant rings) and coordinate with owner IT for secure connectivity
• Guide field & commissioning technicians on sequencing, test scripts, and punch‑list resolution

• Maintain and evolve STC global PLC code standards, cybersecurity hardening checklists, and simulation workflows
• Evaluate emerging PLC platforms and developer tool chains to improve build velocity and quality

• Mentor junior programmers and apprentices; deliver knowledge‑transfer workshops for owner operations teams
• Manage team issues and KPI dashboards for internal and client reporting and continuous improvement

• Technical Mastery: 10+ years hands‑on programming with Allen‑Bradley Control Logix/Compact Logix
• Application experience:
  Demonstrated HVAC and/or process systems including chilled water plants and temperature, pressure and flow control implementation
• Protocol…