Kiss your PLC

Abstract The sage adage, “ Keep it small and simple ,” provides a memorable acronym (KISS) and good advice for any venture involving complex computers. Yesteryear efforts to incorporate this technology into the traditionally conservative realm of water and wastewater engineering all too often overlooked this KISS approach, however, falling headlong into an electronic abyss that still haunts those plants that strayed too far too fast. Hence, the field has recently begun to shift downward in scale and sophistication, towards a hardware grouping largely dominated by a low-end product known as a programmable logic controller (PLC). Indeed, these PLC's systems appear to offer a prime opportunity for small-to-medium scale water and wastewater treatment facilities to explore a wide range of monitoring and control regimes with minimal financial risk…fully within the KISS context! This paper will, therefore, explore the conceptual development of three small-scale PLC applications that largely emphasize a process oversight or “caretaker” role, but which also have clear potential to incorporate additional missions and responsibilities relative to their affiliated control requirements.