How do you integrate process analyzers with a DCS for closed-loop control?

Analyzer-DCS integration design: communication (4-20 mA for simple, Modbus/OPC for status and diagnostics), signal validation (analyzer status bits, range checking, rate of change limits), measurement dead time compensation (dead time block, Smith Predictor), control strategy (cascade or direct control depending on dynamics), failover logic (last good value, manual backup, safety limits), and calibration impact (auto-hold during calibration cycles). Configuration: DCS function blocks for validation, trending for troubleshooting, and alarming for analyzer health. Test complete loop including failure modes. Document measurement delays and control strategy rationale. Consider: multiple analyzers for redundancy in critical applications.