The ATC990 is Dynisco's current-generation 1/4 DIN PID process controller, engineered primarily for plastics extrusion and melt processing applications where pressure and temperature must be controlled simultaneously from a single instrument. It directly accepts strain gauge bridge inputs from melt pressure transducers (350 to 5000 Ω, 1.4 to 4 mV/V, with 10V excitation) alongside standard thermocouple and analog inputs — eliminating the separate signal conditioner that most general-purpose PID controllers require for pressure measurement. The adaptive auto-tuning algorithm continuously optimizes PID parameters against process dynamics, while the 50 ms sampling rate captures fast pressure transients that slower controllers would miss.

How does the ATC990 differ from the ATC880 it replaces?

The ATC990 brings several architectural upgrades over the legacy ATC880. The monochrome graphical LCD replaces segmented displays with a trend-view screen showing process value, setpoint, and alarm history over time — giving operators at-a-glance process context that a numeric display cannot convey. The backlight changes color on alarm (red) for immediate visual notification across the factory floor. A setup wizard auto-launches on first power-up, guiding the commissioning technician through input type, output range, and alarm configuration in sequence. Optional USB and Ethernet (Modbus TCP) interfaces extend connectivity beyond the standard isolated RS-485, and optional data logging writes process values, setpoints, and alarms to CSV files for quality documentation without external recorders.

What control strategies does the ATC990 support?

Beyond single-loop PID control, the ATC990 supports differential pressure control when equipped with an optional secondary strain gauge input — measuring pressure drop across a melt filter or die to trigger backflush or screen-change sequences before clogging impacts product quality. The 4 programmable digital inputs accept voltage-free contacts for functions such as setpoint selection between two production recipes, auto/manual transfer, alarm acknowledgment, and integrator reset. Control and retransmission outputs are available as 0–5/0–10 VDC or 0–20/4–20 mA with 15¾-bit resolution, providing smooth, step-free drive signals to heaters, motor drives, and proportional valves.