PL2303HXD ===>Device Descriptor<=== bLength: 0x12 bDescriptorType: 0x01 bcdUSB: 0x0110 bDeviceClass: 0x00 -> This is an Interface Class Defined Device bDeviceSubClass: 0x00 bDeviceProtocol: 0x00 bMaxPacketSize0: 0x40 = (64) Bytes idVendor: 0x067B = Prolific Technology, Inc. idProduct: 0x2303 bcdDevice: 0x0400 PL2303TA ===>Device Descriptor<=== bLength: 0x12 bDescriptorType: 0x01 bcdUSB: 0x0200 bDeviceClass: 0x00 -> This is an Interface Class Defined Device bDeviceSubClass: 0x00 bDeviceProtocol: 0x00 bMaxPacketSize0: 0x40 = (64) Bytes idVendor: 0x067B = Prolific Technology, Inc. idProduct: 0x2303 bcdDevice: 0x0300 PL2303HX(A)/XA ( EOL : PHASED OUT SINCE 2012 ) ===>Device Descriptor<=== bLength: 0x12 bDescriptorType: 0x01 bcdUSB: 0x0110 bDeviceClass: 0x00 -> This is an Interface Class Defined Device bDeviceSubClass: 0x00 bDeviceProtocol: 0x00 bMaxPacketSize0: 0x40 = (64) Bytes idVendor: 0x067B = Prolific Technology, Inc. idProduct: 0x2303 bcdDevice: 0x0300 You can use the two fields bcdUSB & bcdDevice to distinguish PL2303HXD / PL2303TA / PL2303HX(A)/XA Johan Hovold <johan@xxxxxxxxxx> 於 2021年2月24日 週三 上午12:51寫道: > > On Tue, Feb 23, 2021 at 11:30:41AM -0500, Michael G. Katzmann wrote: > > On 2/23/21 11:14 AM, Johan Hovold wrote: > > > I only have an HXD (and a GC) here. > > > > > > The HXD has bcdUSB as 1.10 unlike your TA with 2.00, but not sure that > > > helps. > > > > Sound promising .. why do you think this is this not reliable? > > Perhaps it is. Perhaps even bcdDevice of 3.00 is enough (includes some > older variants that the TA replaced supposedly). Not sure anyone ever > tried the current scheme on those older models. > > Charles, could you post the output of "lsusb -v" for your PL2303TA? And > did you verify that you actually got 110 Bd with the current Linux > driver? > > Johan