The Yudian AI-518 is an intelligent PID process controller built around a proprietary AI auto-tuning algorithm that continuously adapts P, I, and D parameters to changing load conditions — eliminating the manual tuning iterations required by conventional PID controllers. Its universal input front-end accepts thermocouples (K, S, R, T, E, J, N, B, WRe), RTDs (Pt100, Cu50), and linear voltage/current signals (0–5 V, 1–5 V, 0–20 mA, 4–20 mA) without hardware changes, making a single AI-518 interchangeable across temperature, pressure, flow, level, and humidity control loops.

How does the AI auto-tuning algorithm differ from standard PID?

Standard PID controllers require the user to initiate a manual auto-tune cycle — typically a full heat-cool oscillation — which captures the process response at one operating point. Yudian's AI algorithm runs continuously in the background, learning the process dynamics during normal operation and adjusting parameters in real time. This self-adaptation handles setpoint changes, load disturbances, and non-linear processes that would de-tune a fixed PID parameter set. For applications that require explicit tuning, the AI-518 also supports conventional AT (auto-tuning), MPT (model predictive tuning), and manual ON-OFF modes.

What input and output modules are available?

The AI-518 features five plug-in module slots — MIO (multi-function input), OUTP (main control), ALM (alarm), AUX (auxiliary/cooling), and COMM (communication) — each accepting a range of interchangeable hardware modules:

• Control Output: Relay (NO+NC, 250 VAC/1–2 A), SSR drive (12 VDC/30 mA), TRIAC (100–240 VAC/0.2 A), linear current (0–20/4–20 mA), or single/three-phase SCR trigger (5–500 A).
• Alarm: Up to four freely assignable alarm outputs — high limit, low limit, deviation high, deviation low — with power-on suppression to avoid nuisance trips at startup.
• Communication: RS485 with MODBUS RTU or Yudian's proprietary AIBUS protocol; optional photoelectric isolation on the S4 module.
• Retransmission: Process value or setpoint retransmitted as 0–20/4–20 mA with 14-bit resolution and 0.2% accuracy.

The controller operates from 100–240 VAC (50/60 Hz) or optional 24 VDC, draws under 3 W, and is available in eight panel-mount form factors from compact 48×48 mm (D2) to full-size 160×80 mm (B), plus a DIN-rail variant (E5). CE, UL, and RoHS certifications are standard.