Challenge

From decreased productivity to system downtime, legacy equipment can pose many challenges to operational efficiency. This was the case for a leading consumer packaged goods company who was relying on PLC-5 hardware to control most of their facility. The plant recently experienced a major disruption during peak production because of a network switch failure, and it was later discovered that the disruption could have been minimized if the facility had been separated into multiple virtual local area networks (VLANs). To support the creation of VLANs, the customer’s existing PLC-5 control system would need to be upgraded to the ControlLogix system which could handle multiple independent Ethernet connections. E Tech Group was called to support the project given their previous assistance with consolidating the company’s DH+ and ControlNet network communications in support of their industrial automation applications.

Solution

E Tech Group performed a comprehensive investigation to identify all PLC types and determine each PLC’s connection to other systems.  After completing their analysis, E Tech Group presented which PLCs were deemed the most critical to upgrade and designed a VLAN separation plan to reduce the likelihood of connection loss given the vast amount of device communications. The customer’s personnel were initially surprised by the number of PLCs that needed to be upgraded to fulfill the VLAN implementation, which was about 21 PLCs. For the best implementation process, it was determined to perform the PLC upgrades in three phases with the first phase switching out the most critical PLCs.

Six PLC-5s needed to be upgraded in the first phase. E Tech Group considered several factors to include local and other server racks, a labor-saving conversion kit, the maintenance of other communications protocols, and ways to thoroughly test the success of the conversion. The customer also requested the migration and testing be completed within 72 hours. With these considerations in mind, E Tech Group worked closely with the customer to determine the best conversion process within the short timeframe. This included the use of only replacing local racks, using DH+/RIO and ControlNet communication modules to support existing networks, complete I/O list development, and spot testing plans. A PLC-5 to ControlLogix conversion tool was utilized to migrate logic from the old hardware to the new hardware, and all drivers were updated in the Wonderware system to allow for proper communication to the new PLCs. DH+/RIO ControlLogix cards were also used to connect into existing DH+ networks and allow ControlLogix PLCs to talk to existing PLC-5 Remote I/O racks.

Results

The project was commissioned on a Friday of a holiday weekend and was completed that Monday. Committed to the success of the project, E Tech Group had two teams supporting the project throughout the entire weekend in 12-hour shifts. In a few short days, E Tech Group was able to have the six PLCs successfully migrated by the customer’s requested timeframe and resolved numerous pre-existing issues within the logic by the time the PLC’s remote monitoring was completed.  Using the knowledge gained during the first phase, the next two phases were completed with much smaller teams and the customer had the ability to improve their operational efficiency with a control system platform.