Logixpro Dual Compressor Exercise 2 «Fully Tested»

“Atlas, you’re up,” she whispered, hammering the HMI start button.

She hit start again.

Atlas roared to life. Pressure stabilized at 96 PSI. For thirty seconds, Maria breathed. Then the production line kicked into high gear—three cappers firing at once, a purge cycle on the filler, and a labeler changeover. The pressure cratered to 85 PSI.

Maria’s fault wasn’t random. It was molten metal and fried bearings. logixpro dual compressor exercise 2

The plant floor at Apex Bottling was a cathedral of stainless steel and hydraulic hiss, but its heart was pneumatic. Two massive air compressors, Titan and Atlas, squatted in the corner, responsible for breathing life into the filling heads, capping machines, and labeling jets. If the air pressure dropped below 90 PSI, the entire line screeched to a halt. If it dropped below 80 PSI, safety interlocks would fire, locking the plant down entirely.

She did the only thing left. She slammed the emergency stop on Atlas, sprinted to the auxiliary air dryer bypass valve, cracked it open to vent a tiny amount of stored air (counterintuitive, but it reduced backpressure), and then reset Atlas’s overload.

That Tuesday, the thermometer on the mezzanine read 104°F. Titan’s cooling fan seized at 2:17 PM. By 2:22, its discharge temperature alarm screamed red on the control panel. The compressor didn't stop—it just kept churning, heating the air to 190°F, expanding it like a furious ghost. The pressure at the receiver tank began to drop. “Atlas, you’re up,” she whispered, hammering the HMI

In the LogixPro simulation, you had ladder logic timers: T4:0 for the “minimum run time” and T4:1 for the “anti-cycle delay.” Maria had no time to program. She had to become the PLC.

Atlas groaned, then spun. The unloader, freed by the pressure relief, clicked open. The compressor started unloaded. Pressure had fallen to 82 PSI—two pounds above disaster.

At 2:30, Maria Chen, the shift electrician, pulled up the LogixPro simulation on her laptop—the training software she’d mastered years ago. But this wasn’t a classroom exercise. This was Exercise 2 for real. Pressure stabilized at 96 PSI

“You just passed Exercise 2 with a gold star,” said the plant manager, handing her a bottle of water.

For the next forty minutes, Maria stood guard. Every 11 minutes, Atlas’s thermal overload would creep toward its limit. She’d manually cycle it off for 90 seconds—just long enough for the header tank’s stored volume to keep the line alive—then restart it. It was brutal, improvisational, and exactly like the simulation’s hardest setting: Manual Fault Recovery.

She jumped to the control cabinet, fingers flying over the old Allen-Bradley pushbuttons. She disabled the automatic lead-lag and forced Atlas into continuous run. Then she saw the problem: Atlas’s unloader solenoid was sticky. The compressor was starting under full load, drawing 300% amperage. The thermal overload relay clicked once, twice—on the third click, it would trip.

She smiled, exhausted. “Yeah,” she said. “But in the simulation, the compressors don’t smell like burnt oil and fear.”

In LogixPro’s “Dual Compressor Exercise 2,” the goal was simple: maintain 90–100 PSI with two compressors, handle duty cycling, and prevent both from running simultaneously for too long to avoid overload. The twist? A random “fault” could disable one compressor, forcing the other to handle the load within strict time limits.