No-source two-wire 4-20mA current loop, compatible with 2, 3, and 4 wire systems. 9 programmable output settings for dynamic testing in real environments; each segment can be configured for run time, A current, and B current. Digital encoder adjustment provides stable performance unaffected by temperature or humidity changes. Capable of positive and negative connection; two-wire system ensures safe operation regardless of wiring configuration, preventing damage to the meter. High precision and excellent linearity (Output accuracy: 0.5%; Display accuracy: 0.01). Features coarse and fine adjustment modes for fast and accurate calibration. Adjustable output range: 4-20mA (control device) or 3-21mA (debug signal). Display modes: Actual current / 100.0% / 50.0Hz, with LCD screen and backlight. Linear output with calibration capability. Selectable automatic or manual output mode. Configurable quick adjustment output points: 2 to 9 points. Built-in low-power consumption chips; no heat generation, ensuring stable output. Durable plastic housing; compact design for easy installation. System Operation: Parameter Settings: Rotate clockwise to increase ("+"), rotate counterclockwise to decrease ("-"), press knob to confirm. 1. Press and hold knob for 2 seconds to enter parameter mode; display shows "F001". Press "Confirm" to set value. =0 for coarse tuning; =1 for fine tuning. Press "Confirm" to save. 2. While viewing parameter number "FXXX", use "+" or "-" to modify the parameter number. Enter password "+ - - +" to access F002. Enter password "+ - + -" to access F100. Enter password "- + - +" to access F200. Power supply voltage: 15V–30V Output range: 4–20mA / 3–21mA Display mode: Real Current / 0–100.0% / 0–50.0Hz Sampling resistance: Less than 500 ohms Output accuracy: 0.5% Display accuracy: 0.01 Item condition: New Quantity: 1 Piece Color: As shown Material: Plastic Size: 79.5 x 42.2 x 24mm / 3.13 x 1.66 x 0.94 inch Package Contents: 1 x Signal Generator Note: Light reflection and display differences may cause slight color variation between image and actual item. Measurement tolerance: ±1–3cm.