When many sites test peripherals, handwriting screens cannot work on VMs, for example, there is nothing on displayed the screen or there is no response to a stylus. These problems usually occur in business halls of carriers
A handwriting screen is a compound device which includes a stylus and a display, which may or may not need drivers. In Device Manager, you can see whether a device is a compound one. Normally, you need to connect the device to a PC, and then there will be a new display in Display Devices and a new device in Human Interface Devices.
Connect a handwriting screen to the PC. Then view the new device in Device Manager (Drivers may need to be installed.)
Use a Wacom handwriting screen as an example.
1. In USB Display Adapters, a new device appears, which is the display and its pid and vid.
2. In Mice and other pointing devices or Human Interface Devices, one or two HID-Compliant Mouse devices appear. (Actually they are the same device). The device is stylus. Because styli and mice or keyboards are similar, they are classified into the same category.
3. A simple way to view a device: Remove and reinsert the device. Then view which device is added in the Device Manager.
As seen from the preceding analysis, a handwriting screen adds more than one device into the Device Manager. However, not all these devices need to be mapped to the VM. You only need to map the stylus (VID=056A PID=00FB) to the VM through USB redirection. The display (VID=17E9 PID=038F) does not need to be mapped. The contents on the display are displayed using Huawei Desktop Cloud Dual-Display technology. The handwriting display equals an auxiliary display. (This is where many customers are making mistakes at their sites.)
1. Add the USB redirection policy ID:056A:00FB: 1: 0|ID: 17E9: 038F: 0: 0 to FusionAccess Portal.
2. On the PC or TC, install display drivers locally. Often drivers are not needed. Most USB displays are produced by DisplayLink (a vendor with vid=17e9) which does not offer Linux drivers. Therefore, Wacom handwriting screens cannot be used on Linux TCs.
3. The handwriting screen software is installed on the VM. When you open the software, a signature window appears on the display of the handwriting screen. If not, the handwriting screen software does not detect the auxiliary display (handwriting display). On the virtual desktop of FusionAccess, the symbolic link for the auxiliary display is \\.\DISPLAY3. If the handwriting screen has a configuration item for its display, change the configuration item to \\.\DISPLAY3.