#20 PLC Best Practices – Identify Critical Alerts
Identify PLC critical alerts and program a trap to monitor the trigger conditions and the alert state for any deviation.
PLC Best Practices
#19 PLC Best Practices – Monitor PLC Memory Usage
Measure and provide a baseline for memory usage for every PLC controller deployed in the production environment and trend it on the HMI.
#18 PLC Best Practices – Store PLC Hard Stop Events from Faults
Store PLC hard stop events from faults or shutdowns for retrieval by HMI alarm systems to consult before PLC restarts.
#17 PLC Best Practices – Log PLC Uptime and Trend it on HMI
Log PLC uptime to know when it’s been restarted. Trend and log uptime on the HMI for diagnostics.
#16 PLC Best Practices – Create Trend for Cycle Time on HMI
Summarize PLC cycle time every 2 to 3 seconds and report to HMI for visualization on a graph using trend.
#15 PLC Best Practices – Safe State when PLC Restarts
Define safe states for the process in case of PLC restarts (e.g., energize contacts, de-energize, keep the previous state).
#14 PLC Best Practices – Restrict Third-party Data Interfaces
Restrict the type of PLC connections and available data for third-party data interfaces in a programmable logic controller,
#12 PLC Best Practices – Validate Inputs based on Physical Plausibility
Ensure operators can only input what’s practical or physically feasible in the process. Learn the PLC’s best rules.
#11 PLC Best Practices – Instrument for Plausibility Checks
Instrument the process in a way that allows for plausibility checks by cross-checking different measurements.
#10 PLC Best Practices – Assign Register Blocks by Function
Assign designated register blocks for specific PLC functions in order to validate data and block unauthorized access to controller data.
