Ratio Control: Blending Two Flows When You Only Get to Control One of Them
In ratio control one stream sets the pace and you trim the other. Where the multiplier goes, why actual ratio drifts, and starting up without off-spec.
Articles
Practical SCADA notes
Field-oriented references for HMI/SCADA systems, industrial communication, alarms, tags, historians, and project delivery.
Split-Range Control: Handing Off Between Two Valves Without a Bump at the Split Point
One PID driving a heating and a cooling valve stalls or hunts right at the changeover. Setting the split point, killing overlap, and the gain jump.
Cascade Control: Why the Slave Loop Has to Be Faster Than the Master
Cascade loops fail when the two are tuned in the wrong order or the slave's limits never reach the master. Commissioning them so they stop fighting.
Making Online PLC Edits Without Tripping the Running Process
Changing ladder logic in a running PLC safely: online edit versus download, scan-order traps, seal-in glitches, forces, and a pre-edit checklist.
Why Your PID Loop Overshoots Every Time the Valve Hits a Limit
Reset windup is why a well-tuned loop overshoots after saturation or a manual-to-auto swap. What anti-windup and external reset actually fix in a PLC.
What is SCADA?
A practical explanation of SCADA systems: what they do, where they fit, and what to watch for on real projects.