Gets the current device handle. You can only call this function in a report, to get the handle of the device where the report is logging. You can then use the other device functions (for example, DevPrint()) to access that logging device. (To get the handle of a device other than a logging device, you need to use the DevOpen() function.)
If the report is logging to a group of devices, this function will return the group handle. However, not all device functions support group handles, for example, you cannot read from a group of devices.
The current device handle or group handle. If no device is configured, -1 is returned.
! Get the report device number.