Consistency in Automation is Achieved with Standard Function Blocks

[Cengiz Özemli]

The use of standard function blocks in automation offers significant technical and economic advantages in municipal water and wastewater automation. Repeatable and cross-platform compatible blocks applied in different facilities provide a solution to code inconsistencies in automation projects.

### Problem: Code Inconsistency

The various PLC platforms (Emerson PACSystems, Rockwell ControlLogix, Rockwell Micro800) used in municipal water and wastewater infrastructure, and custom programming based on customer demands, cause difficulties in operation and maintenance processes. Unique programming requires writing motor control, valve sequencing, and analog processing codes from scratch for each facility, significantly increasing engineering time.

### Solution: Cross-Platform Function Block Library

A comprehensive function block library designed for water and wastewater applications has been developed, running on three different PLC platforms:

• Rockwell ControlLogix/CompactLogix (Studio 5000, add-on instructions)
• Rockwell Micro800 (Connected Components Workbench - CCW)
• Emerson PACSystems RX3i (PAC Machine Edition)

### Core Function Blocks

• Advanced motor and pump control: VFD integration, runtime tracking, and predictive maintenance.
• Smart valve control: Automatic valve sequencing with position verification and travel time monitoring.
• Analog signal optimization: Scaling, totalization, and priority-based alarm management.
• Pump alternation sequencing: Automatic rotation and runtime equalization for up to 10 pumps.

Each block includes Hand-Auto control, alarm management, runtime tracking for predictive maintenance, and a simulation mode that allows operational testing without physical I/O.

### Design Philosophy

Functional equivalence is aimed for with platform-specific optimizations. The blocks are designed to be configurable by technicians, and the simulation capability allows testing without interfering with live systems.

### Project Efficiency and Quality Gains

• Programming time reduced by 85%, bringing motor, valve, and analog operations down to approximately 30 minutes.
• Engineering hour savings exceeded 1,200 hours, which translates to a cost advantage of approximately $120,000.
• Commissioning errors decreased from 15-20 to 2-3, while troubleshooting time dropped from 4 hours to 30-60 minutes.
• Code similarity increased from 30% to 95%, accelerating new operator adaptation time by 40%.

### Industry Acceptance and Application

This approach provides standardization across multiple PLC platforms and creates a scalable, customizable framework. It offers ease of use and reduced project costs for engineering firms, municipalities, and system integrators.

### Example Application

In an upgrade project for an 8 million gallons/day wastewater treatment plant, traditional programming took 140 hours, while with function blocks, it was completed in just 24.5 hours. Commissioning and operator training processes were significantly shortened.

### Future and Development

With the released version 3.0, features such as cybersecurity, cloud connectivity, advanced fault diagnostics, and energy optimization are being added. The goal is to achieve widespread standard application in the industry and increase consistency in water/wastewater automation.

This function block library proves that automation standardization is both technically and economically viable and valuable.