The controllers used in web handling have a lot of data, but not much storage capacity. Many manufacturers recognize this and collect and retain the data from the drive controller using programs typically including the word “Historian." This may be used for equipment maintenance and to track customer orders and shipments.
The drive system controls speed, tension, roll lengths and diameters. Generally, the same controller regulates other roll quality parameters such as nip loading and torque split. It may also contain information related to product ingredients, treatments and coating formulations.
The drive controller has a short memory. That is all that is required for control. Long term data storage must be done on another computer. The computer may be the operator HMI, but will probably be a database on a corporate server. Special software and network communications equipment are required to communicate between the database and the controller.
Control engineers often think of data vs. time. It may be more useful to store data by roll # or order #. This is possible with correct programming. This requires programming work by database and control personnel.
The amount of data collected is truly amazing. When problems or complaints occur, it takes a long time to review the historian data to determine the fault. Analytics properly applied could help sort through the data to seek problems causing customer complaints. Eventually, the analytics may even help with preventative maintenance and in preventing defects from reaching the customer.