Case Study: GEMCO Automation System Upgrade



To upgrade the entire PLC hardware system of the concentrator plant from legacy Siemens S5 to Siemens S7 PLCs and to integrate the new PLC to the Citect SCADA system.


The GEMCO manganese processing plant on Groote Eylandt in Gulf of Carpentaria, Northern Territory consisted of 3500 I O distributed in 8 interdependent legacy PLC’s networked around the site. The PLC’s and communication network had become increasingly unreliable with sporadic failures. Spares were no longer available, to a point where the plant would no longer be supportable, even in the short term. Given this, the remote location of the site and the technological advantages that an up to date PLC offered, it was decided to replace the PLC’s in their entirety. GEMCO envisaged in their request for tender that the PLC change over would take 4 weeks and planned accordingly, making allowance for the loss of production.

The project presented I S Systems with unique challenges due to the scope and time frame for the replacement. 8 PLC’s and wiring for 3500 IO had to be installed and commissioned in a very short time span. Not only that but the existing SCADA of 7000 tags and 30 individual Citect stations around the plant had to be considered and converted as well. Non time critical aspects of the job such as software engineering and communication networks (this could all be undertaken separately without the plant having to be shut) would have to be guaranteed absolutely correct. These difficulties had to be addressed at both an engineering and project management level.

I S Systems completed the site installation testing, site verification and commissioning in 2 normal plant maintenance shutdowns of 24 hours each with the commissioned changeover taking place in just 100 hrs. Plant startup with the new PLC’s was seamless with no loss of production.

Client: GEMCO

 GEMCO automation systems