12.2 Flowchart of the recommended steps for risk mitigation
12.3 Example network architecture that shows how a typical network can be designed with built-in “defense-in-depth”
13.1 Situational awareness
13.2 Panels designed for human interaction
13.3 Alarm states
13.4 Issues to consider when determining control panel locations
13.5 Mobile HMI displays
13.6 Example of a console configuration with defined operator stations and various-sized displays for HMI monitoring and control. Use of stackable displays should be carefully evaluated
13.7 Example of a console arrangement in a control and server room layout
13.8 Overview treatment facility HMI graphic using P&ID display approach
13.9 Human–machine interface graphic using three-dimensional design approach for a scrubber system showing process and detail displays
13.10 A partial HMI display hierarchy showing typical tiers of information display at a WRRF
13.11 Example of a process detail display for a chlorination system using the next generation design method
13.12 Example of data using a digital (a) vs an analog (b) method of display
13.13 Example of a moving analog indicator with optional enhancements
13.14 Example of a trend using roadmap
13.15 Examples of a profile display and pattern recognition object radar plot
13.16 Alarm priority distribution graph—best practice vs actual
13.17 Human–machine interface priority alarming methods
13.18 Benchmarking the alarm system—alarming rates exceed operator handling capability
14.1 The scan cycle of a PLC
14.2 Allen-Bradley ControlLogix Analog Output Module, 1756-OF4
14.3 Analog input scaling block
14.4 Fine-screen slide gates—control narrative example
15.1 Maintenance progression
15.2 Maintenance work flow diagram
15.3 Calibration curve for laboratory reference dissolved oxygen probe
15.4 Graph comparing field and references dissolved oxygen probes
15.5 Percent recovery control chart for laboratory reference probe
15.6 Shewhart control chart for aeration basin no. 1 dissolved oxygen probe
16.1 Dick and Cary Systems Approach Model
16.2 Viable training development model
16.3 On-the-job training sample task sheet
16.4 Sample training module
16.5 Training module design
List of Tables
2.1 Operating costs for a typical WRRF
2.2 Life expectancies of typical control system devices
2.3 Calculation of present worth
3.1 Various design documents and industry standards
3.2 A sample list of monitored variables
3.3 A sample description of an alarm control strategy
3.4 An example of a milestone schedule for a typical control system design for a WRRF
5.1 Sample equipment operating table
7.1 Possible steps in a two-pump station
7.2 Advantages and disadvantages of ANN models
7.3 Types of ANNs and their application areas
8.1 National Electrical Manufacturers Association’s codes for enclosures
8.2 Internal protection digit definition
8.3 National Electrical Code ratings for enclosures
8.4 The ATEX classification
8.5 Typical protocol
8.6 Standards-setting organizations
9.1 Typical flow meter characteristics
9.2 Flow meter applications
9.3 Effect of flow disturbances on the accuracy of transit time flow meters