labelwriter / web/src / WebLabelWriterPrinterOptions
Interface: WebLabelWriterPrinterOptions
Properties
engine?
optionalengine?:PrintEngine
The engine this instance is scoped to. Defaults to device.engines[0] — back-compat for single-engine LWs (3xx/4xx/5xx) and the Twin Turbo (single shared transport, in-band ESC q routing on the primary).
For multi-interface composite devices (Duo family — label on IF 0, tape on IF 1) callers must construct ONE instance per engine, each with its own Transport claimed against the engine's bind.usb.bInterfaceNumber. The encoder dispatches by engine.protocol, so per-engine print() writes the correct protocol bytes (lw-raster vs d1-tape) to the correct endpoint.