Aftermarket Automation PublicationsField notes on legacy controls, software, protocol recovery, and modernization.https://aftermarketautomation.com/Integrating a New PLC With an Existing Brownfield Control Systemhttps://aftermarketautomation.com/publications/integrating-a-new-plc-with-an-existing-brownfield-control-system/https://aftermarketautomation.com/publications/integrating-a-new-plc-with-an-existing-brownfield-control-system/A practical guide to brownfield PLC integration through PLC coexistence planning, field I/O verification, interface contracts, shadow-mode testing, staged cutover, and rollback.Fri, 06 Nov 2026 00:00:00 GMTPLC Integrationbrownfield PLC integrationPLC coexistencefield I/O inventoryprotocol gatewayshadow-mode commissioningstaged cutoverrollback criteriaDiagnosing Modbus Communication Errors: Timeouts, Addressing, Framing, and Data Formatshttps://aftermarketautomation.com/publications/diagnosing-modbus-communication-errors-timeouts-addressing-framing-and-data-formats/https://aftermarketautomation.com/publications/diagnosing-modbus-communication-errors-timeouts-addressing-framing-and-data-formats/A systematic Modbus RTU workflow for separating timeouts, exception codes, framing faults, addressing errors, gateway delays, and incorrect data formats.Sat, 31 Oct 2026 00:00:00 GMTModbus TroubleshootingModbus communication errorsModbus RTUModbus exception codesregister addressRS-485CRC failureword orderA Systematic Approach to PLC Troubleshooting and Maintenancehttps://aftermarketautomation.com/publications/plc-troubleshooting-and-maintenance-a-systematic-fault-finding-workflow/https://aftermarketautomation.com/publications/plc-troubleshooting-and-maintenance-a-systematic-fault-finding-workflow/An evidence-driven workflow for isolating discrete PLC I/O faults, verifying repairs, documenting findings, and improving preventive maintenance.Sat, 17 Oct 2026 00:00:00 GMTPLC TroubleshootingPLC troubleshootingPLC maintenancediscrete I/Oinput moduleoutput modulepreventive maintenanceMigrating PLC-5 to ControlLogix Without Changing Required Machine Behaviorhttps://aftermarketautomation.com/publications/migrating-plc-5-to-controllogix-without-changing-required-machine-behavior/https://aftermarketautomation.com/publications/migrating-plc-5-to-controllogix-without-changing-required-machine-behavior/A practical guide to converting PLC-5 logic to ControlLogix while preserving required machine behavior through architecture review and equivalence testing.Mon, 28 Sep 2026 00:00:00 GMTPLC MigrationPLC-5 to ControlLogixPLC-5 migrationmachine behaviorI/O bufferingbehavioral equivalenceRSLogix 5