Safety PLC Coding Practices – Programming Recommendations
In this article, we will learn the Safety PLC coding practices and the best tips you can follow when programming a safety PLC function.
In this article, we will learn the Safety PLC coding practices and the best tips you can follow when programming a safety PLC function.
In this article, you’ll find the PLC programming best practices and tips to take into consideration before and while writing a PLC code.
Identify PLC critical alerts and program a trap to monitor the trigger conditions and the alert state for any deviation.
Measure and provide a baseline for memory usage for every PLC controller deployed in the production environment and trend it on the HMI.
Store PLC hard stop events from faults or shutdowns for retrieval by HMI alarm systems to consult before PLC restarts.
Log PLC uptime to know when it’s been restarted. Trend and log uptime on the HMI for diagnostics.
Summarize PLC cycle time every 2 to 3 seconds and report to HMI for visualization on a graph using trend.
Define safe states for the process in case of PLC restarts (e.g., energize contacts, de-energize, keep the previous state).
Restrict the type of PLC connections and available data for third-party data interfaces in a programmable logic controller,
Ensure operators can only input what’s practical or physically feasible in the process. Learn the PLC’s best rules.