Process Control

Monitor and control of a heavy industry process. The system collects process data for improvement of the process and tracks consumables through the process from initial receipt to final delivery.
Project Index
 Synopsis Description of this project.
 Required Hardware Hardware utilized for this project.
 Required Software Software packages utilized for this project.
 Environment Installation physical and logical environment.
 Application Interfaces Interactions with other systems.

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Synopsis:

The primary objective is the recovery of marketable material from scrap. Some of the material is pre-processed before the actual extraction is done in order to increase the yield.

The purpose of this system is to control of all the equipment from HMI terminals in an operator's booth during normal operation, or from OIT terminals on the floor. The control booth can be staffed with several operators during periods of peak manual activity, or by a single operator when the material being processed permits more automated handling.

Material enters the process from rail or truck deliveries in bulk or bales. All bulk and some baled material is shredded before being stored in bins for additional processing. The shredded material is handled automated conveyors and hoppers. Some high density bulk material is loaded directly into the process by front-end loaders.

The shredded material may be loaded directly into the main process, or routed through a pre-processor to improve yield. The pre-processor does not have adequate capacity to handle all of the shredded material.

Material that is manually handled is identified by bar code tags that are scanned by the material handling operators. This verifies that the proper material is being processed, and tracks the consumption of material by lot into resulting batches. A chemical analysis is done for each batch, automatically recorded in the data base, and delivered to the customer with the material.

All arriving and departing material is weighed on scales connected directly to an application program running on an NT server. Arriving loads are tracked by the trailer number when weighed in, unloaded and weighed out. This allows scale tickets to show not only arrival and departure weight and time, but also process identification and warehousing information in addition to net weight. A permanent record is made for each load in the data base and associated with a unique lot number. This lot number is identified when the material is processed. It is possible to associate each batch of product with a lot or combination of lots used in its production.

The system controls motors from 1 hp to 500 hp. Most are forward-stop-reverse conveyor drives, some are on/off blowers or pumps, but 3 of the largest motors are reversable, variable speed drives that use feedback loops to tightly control the speed. All of the direct control of motion is through Allen-Bradly Programmable Logic Controlers (PLCs). There is a variety of discrete and analog inputs and outputs interfaced to these units.

All HMI data entry is validated by Cimplicity Basic Control Engine (BCE) scripts against the Cimplicity real-time database or the ORACLE master files. Some process data is collected directly into ORACLE and displayed on the HMI screens.

A remote NT Server is equipped with software capable of backing up any shared directory in the domain. It also has software to create archive copies of data onto a CD-ROM.

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Required Hardware:

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Required Software:

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Environment:

The PLC and motor control hardware are installed in concrete block rooms to protect them from the heat and heavy material handling equipment. All of the PCs are installed in normal industrial office conditions, but there is a higher than normal level of dust.

All of the PCs, PLCs and plain paper printers are connected to the plant's LAN. There are two 10BaseT hubs with bridges to the fiber optic enterprise backbone. One hub is near the control room, the other is across the facilty at the foreman's and receiving clerk's offices. The member NT Server in this area interfaces with the scales, lab equipment and serves as the telnet host for the RF scanners and terminals.

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Application Interfaces:

The only 'external' interface is the transfer of data from the local ORACLE database to the enterprise data warehouse.

Interfaces on the LAN are exclusively TCP/IP. This is the only protocol installed on the equipment. A standard NT Domain controls security and resource (disk file and printer) sharing.

A stand-alone NT Server that is a trusted member of the domain has multiple serial ports. This is the interface for equipment that is better served by a computer than a PLC. It communicates with the Metler Toledo truck scale and industrial platform scale (40,000 lb capacity) via 20ma loops. There is also a 20ma loop interface to the scale ticket printer. An RS-232 connects this server to the spectral analyzer.

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Created by Gary England
Last Revised: Sunday, January 4, 1998

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