The cross-platform function block library illustrates that standardization within municipal water and wastewater automation is both technically viable and economically advantageous. Achieving standardization through reusable function blocks is practical, beneficial and merits investment. The demonstrated success across various facilities indicates that employing comprehensive, reusable function blocks should be regarded as standard practice rather than an isolated initiative.
Challenge: Reinventing the wheel
Municipal water and wastewater utilities face a persistent automation challenge: code inconsistency. Despite operating similar equipment across multiple facilities, each project typically receives custom programming, which can create operational headaches and maintenance nightmares.
The root causes are familiar. Some legacy systems use Emerson PACSystems, newer installations favor Rockwell ControlLogix and remote sites employ cost-effective platforms such as Rockwell Micro800. This vendor diversity is inevitably dictated by budget constraints, existing infrastructure and procurement processes spanning decades.
Custom code compounds the problem. Even for identical functions, engineers write new motor control, valve sequencing and analog processing code for each facility. One mid-sized utility calculated 35 to 40 engineering hours for a typical four to five pump lift station. Multiply that across dozens of similar facilities, and the inefficiency becomes staggering.
The business impact is substantial: inconsistent operator interfaces, repeated commissioning bugs, extended troubleshooting times and frustrated staff transferring between facilities expecting consistent operation but encountering completely different control philosophies.
Solution: Cross-platform function block library
The answer is a comprehensive library of reusable function blocks designed specifically for water and wastewater applications, implemented across three programmable logic controller (PLC) platforms with functional consistency maintained despite platform differences.
Platform coverage:
- Rockwell ControlLogix/CompactLogix (Studio 5000 using add-on instructions)
- Rockwell Micro800 (Connected Components Workbench [CCW] using function blocks)
- Emerson PACSystems RX3i (PAC Machine Edition using function blocks).
Core function blocks:
- Advanced motor/pump control: Comprehensive motor control with variable frequency drive (VFD) integration, runtime tracking and predictive maintenance features.
- Intelligent valve control. Automated valve sequencing with position verification and travel time monitoring.
- Analog signal optimizer. Multi-function analog processing including scaling, totalization and priority-based alarm management.
- Pump alternation sequencer. Automated lead-lag rotation for up to 10 pumps with runtime equalization
Each block incorporates features critical to water/wastewater operations: Hand-Off-Auto control, comprehensive alarm management, runtime tracking for predictive maintenance and critically simulation modes enabling complete factory acceptance testing (FAT) without physical input/output (I/O).
Design philosophy: Platform-appropriate implementation
Creating function blocks that work across different PLC platforms requires more than code translation. The design prioritizes functional equivalence over code identity. Rather than forcing identical implementations, each platform version is optimized for that environment while maintaining consistent external behavior and operator interfaces.
Key design decisions:
- Comprehensive versus minimal: Incorporate every potentially needed feature rather than creating minimal blocks requiring frequent modification.
- Configuration versus programming: Blocks are designed to be configured by technicians rather than requiring ladder logic expertise.
- Embedded intelligence: Blocks incorporate common scenario handling directly rather than relying on external logic.
- Simulation capability: Each block operates in simulation mode, generating realistic feedback signals for risk-free testing.
The simulation capability has proved to be transformative. Traditional commissioning involves debugging on live processes, which is risky and time-consuming. With simulation mode, complete control sequences, alarm handling and human-machine interface (HMI) integration can be verified during FAT without physical equipment.
Quantified results
Engineering time savings. Traditional custom programming requires three to four hours per motor, valve or analog point. With the function block library, motor/pump implementation takes around 30 minutes (85% reduction), valve implementation takes around 30 minutes (85% reduction) and analog processing takes around 30 minutes (85% reduction).
Across hundreds of deployed instances, this represents more than 1,200 hours of engineering time savings, equivalent to more than $120,000 in labor costs.
Quality improvements. Commissioning data reveals that discovered issues are reduced from 15 to 20 per project to two to three per project. The remaining issues are configuration errors, not logic bugs. Troubleshooting time is reduced from more than four hours to 30 to 60 minutes per issue. In addition, there is a 60% reduction in post-startup control-related service calls.
Consistency gains:
- Code similarity improved from around 30% to around 95% across facilities.
- New operators are productive 40% faster when transferring between sites.
- Troubleshooting procedures are applicable across all sites.
- Self-documenting code reduces external documentation burden.
Industry validation: Adoptable methodology
The strongest validation of this approach lies in its transferability and potential for widespread industry adoption. The function block architecture and cross-platform implementation methodology represent a replicable framework that engineering firms and utilities can adapt to their specific environments and requirements.
Key adoption advantages are platform flexibility, scalable implementation and a customizable framework:
Platform flexibility. The methodology works across multiple PLC vendors, which allows firms to implement standardization regardless of their preferred automation platform.
Scalable implementation. Organizations can start with one platform and expand to others as needed, rather than requiring wholesale platform changes.
Customizable framework. While the core principles remain consistent, specific function blocks can be modified or expanded to meet unique operational requirements.
Industry applicability. This standardization approach addresses universal challenges in municipal automation. Engineering firms can develop their own standardized libraries, reduce project costs and improve consistency across clients. Utilities can implement cross-facility standardization even with mixed vendor environments. System integrators can differentiate themselves by offering pretested, comprehensive function block libraries. Training organizations can develop curriculum around standardized automation practices
Transfer methodology. The development process itself is replicable:
- Identify the most common control functions across projects.
- Design comprehensive blocks incorporating typical requirements.
- Implement simulation capabilities for risk-free testing.
- Create platform-specific optimizations while maintaining functional consistency.
- Document extensively for widespread adoption.
This approach transforms automation standardization from a theoretical goal into a practical implementation strategy that organizations across the industry can adopt and customize for their specific needs. The methodology’s success demonstrates that comprehensive function block libraries should become standard practice rather than exceptional effort.
Case study: Real-world impact
A recent eight million gallons per day (MGD) wastewater treatment facility upgrade illustrates the impact. The project included multiple motors/pumps, automated valves and analog instruments on a ControlLogix platform.
- Traditional approach estimates: 140 programming hours
- Function block approach actual: 24.5 hours
- Savings: 115.5 hours on programming alone.
Additional benefits:
- FAT: three days versus typical five to seven 7 days
- Site commissioning: four days versus typical seven to 10 days
- Operator training: two days versus typical four days.
What worked well. Comprehensive initial design paid dividends because minimal field changes were required across hundreds of deployments. Simulation capability delivered outsized returns despite significant development effort. Platform-specific optimization produced more efficient code than forced standardization.
Challenges encountered. Initial resistance to “black box” functions required demonstration and education. Configuration complexity needed clear guides and examples. Version control across platforms required discipline and formal processes.
Looking forward
The function block library continues evolving based on field experience. Version 3.0 development includes cybersecurity features, cloud connectivity preparation, enhanced diagnostics with predictive failure detection and energy optimization algorithms.
The goal is industry-wide standardization. If these function blocks or similar approaches become de facto standards across water/wastewater automation, the collective benefits would be enormous: reduced engineering costs, improved reliability, easier knowledge transfer and accelerated deployment of advanced capabilities.
This cross-platform function block library demonstrates that standardization in municipal water/wastewater automation is both technically feasible and economically compelling. More than 1,200 hours of documented time savings, significant quality improvements and the adoptable methodology validate the approach.
For utilities struggling with code inconsistency and custom development costs, the message is clear: standardization through reusable function blocks is achievable, valuable and worthy of investment. The success across multiple facilities suggests comprehensive, reusable function blocks should become standard practice rather than exceptional effort.
