var instance = new Vintasoft.Twain.WebTwainDeviceDocumentFeederJS(device);

var value; // Type: boolean
value = instance.get_DuplexEnabled();

function get_DuplexEnabled() : boolean;

Return Value

This property sends a synchronous request to get value of WebDeviceCapabilityIdEnumJS.DuplexEnabled capability. If you want to use asynchronous request instead of synchronous request, please get information about WebDeviceCapabilityIdEnumJS.DuplexEnabled capability using WebTwainDeviceJS.getCapabilityAsync or WebTwainDeviceJS.getCapabilitiesAsync function.

Reference

WebTwainDeviceDocumentFeederJS Class
WebTwainDeviceDocumentFeederJS Members