Thunder Valley Amusement
Ride Control Safety Documentation
GuardLogix safety system controlling a roller coaster block section. ASTM F24 audit is in 90 days and the park has zero documentation on the safety PLC logic. The original ride integrator was acquired and the engineers moved on. See how Controls Foundry builds the audit package.
Train Speed
42.7ft/s
Block Occupancy
CLRstatus
Brake Pressure
112psi
Dispatch Ready
RDYstatus
What's Running at This Park
A GuardLogix safety system, distributed safety I/O, and an HMI with no source files. The ASTM F24 auditor wants to see everything.
BLK-CTRL — Block Section Controller
GuardLogix 1756-L73S
Safety-rated block section controller managing 6 block zones on the main coaster. Dual-processor architecture with safety partner. Handles train spacing, speed limiting, and emergency stop sequencing. No documentation since 2014 installation.
DSP-01 — Dispatch Console
PanelView Plus 7
Operator dispatch station with PanelView HMI. Displays block status, train positions, and dispatch readiness. The HMI communicates with the GuardLogix over EtherNet/IP — but the screen layouts were built by a contractor who left no source files.
ESTOP-NET — E-Stop Network
Point I/O Safety
Distributed safety I/O network with CIP Safety over EtherNet/IP. 14 emergency stop stations around the ride path, each with hardwired inputs to Point I/O 1734-IB8S safety modules. All feed into the GuardLogix safety task.
Live Preview
This is what Controls Foundry looks like when monitoring your equipment.
Signal Dashboard
Train Speed (Brake Zone 1)
Train Speed (Brake Zone 2)
Train Speed (Station)
Dispatch Count
Headway Timer
Annotated Ladder Logic
Ride enable gate. Three conditions must be true: maintenance key switch in RUN (not MAINTENANCE or OFF), no E-stop buttons pressed anywhere on the ride, and the GuardLogix safety task reporting healthy. This is the master gate for all ride operation.
Block 1 occupancy set. When the entry proximity sensor detects a train entering block 1 and the exit sensor is still clear, the block is latched occupied. This is the fundamental block section safety principle — a block is occupied from the moment the train enters until it fully exits.
Block brake hold. If block 2 is occupied AND block 3 (ahead) is also occupied, the block brake between them applies to prevent a collision. This is the core of the block section safety system — no two trains can be in adjacent blocks without a brake holding the trailing train.
Overspeed trip at brake zone 1. If train speed exceeds 55 MPH (design max of 50 MPH plus 10% safety margin), the overspeed trip latches and all brakes apply immediately. This protects against structural loads exceeding the design envelope. The trip requires a maintenance key reset.
and 9 more rungs annotated...
HMI Process View
How Controls Foundry Works
From undocumented safety PLC to ASTM F24-ready audit package — in three steps.
Upload & Parse
Upload the GuardLogix L5X export and Controls Foundry separates standard and safety tasks automatically. Safety-rated I/O points are flagged and tracked independently.
Distinguishes safety task, safety tags, and standard controller logic.
Document & Annotate
AI-annotated descriptions explain block section interlocks, speed check logic, brake sequencing, and E-stop response chains. Cross-reference shows the full safety chain from sensor to actuator.
Safety-critical rungs highlighted with SIL-rated tag tracking.
Plan Migration
Extract behavioral test cases from recorded ride cycles, map safety I/O to new hardware, and build an ASTM F24 documentation package with full traceability.
Complete audit trail from PLC logic to documentation to test results.
Related Reading
ASTM F24 Compliance: Documenting Safety PLCs
ASTM F24 requirements, GuardLogix safety tasks, block section logic, and why ride control documentation is often missing.
Read moreUnderstanding L5X Files
Everything you need to know about Rockwell's L5X export format — structure, tags, programs, and parsing.
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