Cedar Rapids Water District
Lift Station Modernization
SLC-500 lift stations running blind between operator visits. Nuisance alarms causing unnecessary truck rolls. See how Controls Foundry delivers visibility into orphaned pump control programs without replacing the PLCs.
Wet Well Level
6.2ft
Pump 1 Current
18.4A
Flow Rate
342GPM
Chlorine Residual
1.8mg/L
What's Running at This District
Eight SLC-500 and MicroLogix processors spread across the collection system and treatment plant. No remote access, no documentation, no spare parts plan.
LS-01 — Lift Station
SLC-500 1747-L551
Primary lift station with duplex pumps — alternating lead/lag logic, high-level alarm, and pump runtime tracking. Original program from 2001, no documentation. Operators drive out to check status.
WTP-CHLOR — Treatment Plant Chlorination
MicroLogix 1400
Chlorine dosing system with residual feedback loop. PID control tuned by the original integrator in 2008 — nobody has touched the tuning parameters since. Compliance reporting is manual.
PRV-01/02/03 — 3 Remote PRVs
SLC-500
Pressure reducing valve stations on the distribution network. Each has an SLC-500 monitoring pressure upstream and downstream with 4-20mA transmitters. No remote connectivity — data is logged locally to a DataView module.
Live Preview
This is what Controls Foundry looks like when monitoring your equipment.
Signal Dashboard
Wet Well Level
Pump 1 Motor Current
Pump 2 Motor Current
Discharge Flow Rate
VFD Speed Command
Chlorine Residual
Level Rate of Rise
Pump 1 Run Hours
Annotated Ladder Logic
System enable gate. The HOA (Hand-Off-Auto) switch must be in AUTO, the emergency stop must be clear, and main 480V power must be confirmed live. All three conditions gate the System_Enabled flag that the pump control logic depends on.
Emergency stop handler. Immediately unlatches both pump run commands and sets the E-stop active indicator. Both pumps stop on the next scan regardless of level or any other condition.
Lead/lag alternation timer. A 24-hour TON timer runs continuously while the system is enabled. When it completes, the lead pump assignment toggles (rungs 3 and 4). This equalizes run hours across both pumps and reduces uneven mechanical wear.
Lead pump start (Pump 1 as lead). When wet well level rises above the lead-on setpoint of 4.0 ft and Pump 1 is the designated lead, Pump 1 starts — but only if it has no active fault. This is the primary level control action.
and 10 more rungs annotated...
HMI Process View
How Controls Foundry Works
From unknown lift station program to documented, tested, migration-ready — in three steps.
Upload & Parse
Upload the lift station SLC-500 programs and instantly see the ladder logic structure — pump alternation rungs, alarm setpoints, timer presets, and I/O mapping.
Supports .RSS exports, .TXT ladder listings, and .CSV data tables.
Document & Annotate
AI-annotated rung descriptions explain the lead/lag alternation, high-level alarm logic, and pump runtime counters in plain English. Cross-reference shows every tag usage.
Typical lift station program: 80-120 rungs, documented in minutes.
Plan Migration
Map old SLC-500 I/O addresses to new CompactLogix hardware, extract test cases from recorded pump cycles, and build a phased cutover plan — one station at a time.
Per-station migration with rollback wiring for zero downtime.
Related Reading
Remote PLC Monitoring for Water Utilities
Why SCADA replacements stall and how to get visibility from existing PLCs without replacing them.
Read moreHow to Read an SLC-500 Without RSLogix
Extract and document your SLC-500 programs using modern tools — no Rockwell license required.
Read morePLC-5 to ControlLogix Migration Guide
What your integrator won't tell you about addressing changes, hidden costs, and the undocumented program problem.
Read more