Ethernet HMIs bring greater operating flexibility

Now able to see production problems as they occur, an Ethernet-based production management system is making valuable production time savings for a components supplier.
A major new production management system designed and installed by Fern Engineering Systems for a major UK manufacturer of automotive parts uses an Ethernet network to provide substantial savings in production time, and the ability to see production problems as they occur, in real time. Central to new system are seventy-one Proface GP2300L HMIs - all of which have Ethernet interfaces as standard. These units provided a simpler and more cost effective method of achieving the factory-wide network than the alternative of equipping existing cell control PLCs with Ethernet modules.

The system installed by Fern Engineering Systems employs seventy-one automated weld cells, running 24 hours a day, 5.5 days a week.

Each cell is controlled by a PLC and integrates a Proface GP2300L HMI to provide Ethernet communications, and also hands-on operator facilities for calling up component parts and maintenance or engineering assistance.

In each of the automated cells, Proface's Pro-Server software is used to collect data from the PLC/HMI via the Ethernet network.

The data is passed to Fern Engineering System's production display, for creation of the necessary reports, and display and updating of production information.

It is also sent to five strategically positioned PC's, which display individual cell performance in real time.

The Fern software in the Production Display counts the number of parts manufactured in each cell against the Production Planners manufacturing plan for the day and displays the data.

The Production Planners manufacturing plan is also contained on an Excel spread sheet, which is updated once per day with data from the production display.

The efficiency of this system with its automatic production of manufacturing figures offers a number of major benefits including: * Approximately 5 minutes extra production time is available each hour, because time sheets do not have to be filled in.

* Accuracy of the figures: the cell only records what has actually been manufactured.

* Real time cell production performance display: the cell production performance is updated each time a component is manufactured; the resultant data is displayed on the Production Controllers PC and on the HMI in each individual cell.

This allows production problems to be addressed as they happen, as opposed to 24 hours later.

In addition to these production benefits, the introduction of Ethernet to the manufacturing facility provides improved data handling - any changes in production data can be made from the control room PC - and also comprehensive plant wide data collection and monitoring.

The latter facility is courtesy of the Proface GP2300L HMIs integrated into each cell.

With their Ethernet connectivity they enable all the machines on the shop floor to be connected together to collect and exchange data.

Fern Engineering chose the Proface HMIs as the modules for the Ethernet system following a system appraisal.

The initial proposal was that Ethernet modules be added to the existing PLCs in the automated cells.

However, this procedure would have entailed considerable downtime while each module was fitted, and the program of its control PLC modified.

Clearly, the costs of going down this route were unacceptable, so another method for achieving the installation using HMIs was considered.

Driving this solution was the fact that the existing control set-up in the cells already included older Proface GP370L HMIs.

Crucially, these units not only had the same panel cut-out and connections as the latest GP2300l's but they could also down load the existing HMI application into the new, seamlessly, without the need for conversion.

Added to these benefits was the fact that the Ethernet cable could be laid while production was still running; and replacing the HMI took less than 20 minutes, so several installations could be completed in one day.

In addition to their communications role, the Proface HMIs also provide an important 'hands-on' function, enabling the operator to call for component parts, maintenance assistance or engineering assistance (robotics engineer).

The operator simply chooses the appropriate assistance required and presses the button on the touch screen.

This activates a wav.file that plays over the tannoy system: it first identifies the appropriate discipline required by playing a signature tune for three seconds, and then confirms the discipline by annunciating it and finally states the production cells number.

When an engineer arrives at a cell he puts his own ID into the HMI screen, taking ownership of the cell.

The non-productive time accrued while the engineer is logged onto the cell is recorded and allocated to the appropriate department.

The ownership of the cell returns to production when either the engineer logs out of the cell or a production operator logs onto the cell.

This recording procedure enables accurate appropriation of machine downtime and response times to facilitate the production of accurate reports of the cell's non-productive periods.