Zone picking & sortation conveyor, fulfilment centre QLD.

6,000 containers an hour. Safety-rated.

Pac Technologies programmed a safety-rated sortation control system for a Queensland fulfilment centre, managing high-throughput parcel and container flow through four induct points, dual transverse conveyors, and three sortation fingers. The system runs on a Siemens S7-1515F safety PLC over ProfiNet, with a Siemens MTP1200 providing the operator interface on the floor.

Zero-pressure accumulation runs throughout the conveyor network. The control program includes energy-saving mode and machine slowdown logic, so motor run time scales with actual demand rather than running flat-out through off-peak periods.

Industry

Logistics

Service

Programming

Location

QLD

Year

2023

Control

Siemens S7-1515F · ProfiNet

HMI

Siemens MTP1200

High throughput, safety requirements, peak-season pressure.

The site needed a single sortation controller capable of handling peak parcel volumes without jams or mis-sorts, while meeting Australian machine safety requirements. Four induct streams run concurrently, all feeding into the same downstream conveyor network. At 6,000 containers per hour the margin for control errors is small: a blocked sortation finger or a mis-timed divert ripples back quickly through the induct queue. The schedule was tied to a peak trading period, so commissioning time was fixed.

Energy management added a second dimension. The system runs around the clock, but throughput drops substantially in off-peak hours. Without slowdown and energy-saving logic, the full conveyor network runs at full speed regardless. The MTP1200 interface needed to serve two different users: operators clearing faults and restarting lanes on the floor, and maintenance staff diagnosing drive and network issues. Putting both audiences on a single screen would have made each task harder.

One safety PLC, four inducts, three fingers.

The S7-1515F was chosen because its integrated safety capability removes the need for a separate safety controller. Safety functions run in the same CPU as the standard motion and conveyor logic, which reduces hardware count and eliminates the inter-controller communication latency you get when safety and standard control are split across two devices. ZPA accumulation lets containers queue without contact pressure across all four induct streams, protecting both product and conveyor mechanics during surge conditions. When one sortation finger is busy, containers hold position rather than pushing into the back of the queue.

Energy-saving and slowdown logic monitors throughput in real time and steps the conveyor network down when demand is low, then ramps back up ahead of production. The MTP1200 was structured into two distinct areas: an operator view focused on lane status, fault acknowledgement, and restart, and a maintenance view with drive diagnostics and ProfiNet device states. Keeping those separate means an operator clearing a jam is not looking at a screen full of drive parameters.

PLC

Siemens S7-1515F (safety)

Network

ProfiNet

HMI

Siemens MTP1200

Induct

Four induct tables

Transport

Dual transverse conveyors

Divert

Three sortation fingers

Accumulation

ZPA throughout

Energy

Energy-saving mode & slowdown logic

Peak throughput, lower energy, reliable operation.

The system achieved rated throughput of 6,000 containers per hour across all four induct streams during peak periods. Automatic mode switching between full-speed and energy-saving operation reduced motor run time during off-peak hours without manual intervention from operators. Mis-sort rates came in at a level consistent with the mechanical design tolerance of the sortation fingers, with no software-contributed diversions recorded in the commissioning period.

• Rated throughput of 6,000 containers per hour sustained across four concurrent induct streams
• Energy-saving mode activates automatically during off-peak periods, stepping down conveyor speeds without operator input
• ZPA accumulation eliminated contact-pressure damage to containers during surge conditions
• Separate operator and maintenance views on the MTP1200 reduced fault clearance time on the floor