Challenge 

The surge in e-commerce operations and expedited shipping demands have caused unprecedented challenges for distribution centers. To keep the pace, many distribution centers are implementing automation solutions to maximize system throughput and reduce fault recovery time. For a global leader in parcel services, it was mission-critical to develop an extensive fault monitoring and package flow control scheme. The parcel services leader commissioned another company to develop PLC (Programmable Logic Controller) programs for their multiple sortation systems; however, the engineering team was challenged with a tight timeline and limited availability. E Tech Group was engaged to quickly develop and troubleshoot the PLC programs as well as lead the system startup and testing.

Solution

To foster seamless parcel routing and pinpoint system abnormalities, their parcel operations required extensive fault monitoring and suppression for Human Machine Interface (HMI) animation and fault logging, conveyor operation, as well as package flow rate tracking. One aspect of maximizing throughput required the monitoring of package flow to adjust the feed rates for optimal input supply without exceeding the max system capacity. Maintaining throughput also relates to fault recovery times. “Proper fault suppression is a result of monitoring the status of every circuit breaker, Ethernet adapter, VFD status, power supply status, and all IO cards in the local and field racks.” explains Vimal Sandhu, E Tech Group Senior Controls Engineer about the importance of a fault isolation system.  “For example, if a particular circuit breaker tripped, the loss of power may cause the PLC(s) to lose communications with numerous field devices. This can result in anywhere from 1 to 100+ unique faults displayed on the HMI. With proper fault suppression logic in the PLC, only the circuit breaker fault will be displayed. With fault suppression, troubleshooting time is greatly reduced which not only helps maintenance, but also aids in reducing system downtime.”

Experienced in PLC program development with sortation and conveyor machinery, E Tech Group prioritized the commission of the primary sorter systems which included diagnosing and correcting errors in the newly developed logic followed by extensive testing. Once completed, the team promptly set up the communication between the PLC and the customer’s warehouse management system. E Tech Group then proceeded with the setup of the numerous conveyor belts that were required to run with the package tracking logic.

Result

With changes satisfactorily completed to the primary sorter systems, E Tech Group was able to direct the former lead engineering team to update the subsequent systems. E Tech Group stayed onboard to support further testing as well as commission the remaining parts of the primary sorter line. Within a few months, the system became fully operational with E Tech Group’s programming support. The parcel services leader was able to fully maximize its large scale distribution center operations, and E Tech Group was later invited to lead the development, startup, and testing of the second phase which included an additional five sortation systems.