Faults detection starts with a root-cause of the problem and becomes the first and the most important part of the Downtime Reduction process. As you can see from the image above, the actual troubleshooting of any fault is conducted with the use of a tablet or a smart phone. A fault detection algorithm will scan of all I/Os states and will flag to the operator what device or process sequence is at fault. Then, if it is a single I/O detection, a name of the device or process step will be displayed on the screen. After identifying the fault location. the machine operator will call electrician to fix the problem by telling him the location of the problem is. That is how a time-consuming task of connecting a maintenance laptop to a PLC, locate a proper machine logic application and running it will be eliminated. As a result, an actual downtime is drastically reduced to several minutes instead of hours.
The following items are the key to a rapid troubleshooting of a control system:
1.Unified Logic. By combining all available and recreated information of any and all parts of the control system and placing them on a single page 12″x18″. Below is a an example of such a drawing:
- Left side: Electrical Schematics of a Pump Control and protection circuitry’
- Left bottom: PLC chassis and modules wiring diagram
- Center Part: PLC ladder logic diagram
- Center bottom: Process and Instrumentation diagram
- Right side: HMI and Operator station
- Right bottom: drawing legend
2. Fault and Alarm Screens. Those screens will be developed for every automation machinery using the following approach:
- Left side: faults and alarms listing
- Center and right side: Current, Normal and Program status of I/O
- Bottom: color legend of alarms on different situations
3. Tablet-HMI Programming. WEB page design in any available programming language will display faults and alarms that will be shown on table-HMI or on a smart phone as shown below:
Communication from this tablet to the PLC is done by installing an Ethernet module, WiFi router, and a WEB server. No additional modification of the original program will take place. All alarming and fault detection algorithm will done on the WEB server, on the tablet-hmi or inside of the plant OPC server.