REQ-004 — 0–5 V control reference (linear) maps to 0–500 mA output

Each channel's output current shall be controlled by a 0–5 V reference/control voltage with a linear transfer function: 0 V → 0 mA, 5 V → 500 mA. The control voltage is supplied by an external DAC — the module has no on-board DAC (see REQ-010).

Apply control voltage across 0–5 V; output current tracks the linear 0–500 mA mapping. Set-point digital resolution/accuracy is governed by the external DAC; the module's V→I conversion tolerance is TBD.