Summary

The Gerken Companies faced a common infrastructure hurdle: legacy systems couldn't handle the increased sensor density and geographic spread of new crushers and conveyors. Expanding their Custar limestone quarry plant required a sophisticated control overhaul. AMPS UniStream-controlled turnkey system matched—and in terms of diagnostic transparency, exceeded—the capabilities of the leading competitors. The result was a robust, scalable limestone production environment, a distributed solution that enables operators to manage the entire multi-location quarry from a central tower PC at 50% of the cost of the nearest rival bid.

The Company

The Gerken Companies operates across Northwest Ohio as a leading supplier of infrastructure services and construction materials. Their Custar quarry is a critical asset, producing high-quality limestone and aggregate for regional asphalt, concrete, and civil projects.

AMPS Industrial Controls, headquartered in Holland, Ohio, is a UL508A panel builder and full-service system integrator. With deep expertise in panel design, application software, and commissioning, AMPS has a long-standing history of deploying Unitronics solutions for complex industrial applications.

The Challenge

In a geographically dispersed quarry, achieving coordinated control without excessive wiring is a major challenge. The Custar quarry operated using a legacy control system. While reliable, the quarry’s expansion into a brand-new, higher-capacity plant required a significant technological leap.

Gerken needed a system that could handle:

• Increased Complexity: Management of multiple stone crushers, trunnions (rotating conveyors), and an extensive array of sensors.
• Physical Distribution: Equipment spread across a vast geographic area, necessitating long cable runs if not architected correctly.
• Cost Constraints: The leading competitor proposed a solution that was double the investment Gerken was looking to make.

Gerken turned to AMPS, trusting their expertise and their ability to engineer a sophisticated solution that balanced performance with budget.

The Solution

AMPS designed a distributed control architecture anchored by Unitronics UniStream PLC + HMI, model US15, which provides a big, 15.6” touchpanel. Three modified shipping containers were placed at the site at strategic locations—MCC1, MCC2, and MCC3—each housing the UniStream controller, motor starters, VFDs, and other peripherals.

• Distributed Hardware: By placing controls locally at each MCC, AMPS minimized cabling requirements. A sub-location was also added specifically for environmental management, controlling high-dust suppression water pumps; pump control communication was implemented via Unitronics’ Ethernet-based I/Os.
• Centralized Command: MCC3 serves as the primary hub. It manages the haul truck dump zone, primary crusher, and surge pile. Crucially, the primary control tower is located here, allowing a single operator to oversee the entire quarry.

Unified Interface: Via VNC, the Unitronics ecosystem allows operators to view and control all networked PLCs from a local PC in the tower.

System Architecture and Control

Benefits / Results

The transition to the new Unitronics UniStream system delivered immediate and long-term value to The Gerken Companies:

• 50% Cost Reduction: AMPS delivered the project at roughly half the cost of the competing proposal from a local competitor, without sacrificing functionality.
• Operational Efficiency: The automated upstream shutdown logic has virtually eliminated downtime associated with manual material cleanouts.
• Remote Visibility: SMS notifications and Alarm Alerts keep operators informed instantly, while VNC viewers provide a "single pane of glass" for the entire facility.
• Scalability: The modular nature of the UniStream platform ensures that as the quarry continues to produce high volumes, the control system can expand to meet future demand.

Alex Foulke, lead engineer at AMPS, had this to say:
“UniLogic lets you build a consistent alarm structure across multiple PLCs. All the fault conditions—overloads, run feedback, communication loss—are time-stamped, categorized, and tied to the process state. So when something trips, the operator sees the root cause, not just the symptom.

Because the UniStreams are exchanging data continuously over Modbus TCP, we can diagnose interlocks and upstream/downstream dependencies from a single screen. That made commissioning faster and it’s what allows maintenance to resolve issues without walking the entire quarry.”