The above image displays a process control system. This display shows many different instrumentation devices, such as tanks, pumps, mixers, heat exchanges, temperature sensors, pressure valves and sensors, flow meters, and controllers. This process of an oil supply system maintains flow rate of oil with a predetermined temperature. Furthermore, there are over 50 digital and analog inputs, several HMI screens with recipes, configurations, settings, alarms, trends, automatic and manual controls of valves and pumps. There are as many digital as analog outputs.
This process does not show any automation control devices or any interaction between controls and the process. Depending on the sophistication of the graphics, one can expect over 15 valve loop controls with on/off, auto/manual, and preset values displays. There are 3 pumps that require local and/or remote control and graphic displays of their status, such as Auto, Manual, Running, On, Off, Normal, Fault, and Alarm. Finally, there are three PID loops with their own screens for programming of different functions, such as PV, low, low-low, hi/hi-hi, ramp, and dead-band, etc.
Reprogramming (if required)
Control system simplification is meant to accomplish the following features:
- Valve control and fault display to be easily checked, when needed.
- Ability to be understood by maintenance personnel. Some PLC codes are written with indirect programming or with protected function blocks.
- All associated documentation including electrical schematics, P&ID – process and instrumentation diagram – with all devices, wiring diagrams, PLC source codes, HMI screens, Operation and Maintenance Manuals must be available or developed if they do not exist.
- With over 10 production machine on the floor it becomes troublesome to remember all components and instruments.
- We offer a Unified Logic Diagram design for every individual part of the control system.
- Maximum flexibility in the motor control and operation is demonstrated in the Downtime Reduction Methodology Course, including motor status, alarms, and faults.
- Unified Control system, including communication, HMI displays, wiring diagrams, and PLC logic will be placed on the same drawing.
Please refer to the following document Introduction to Downtime Reduction Course located here.