Black Box ServSwitch Freedom Appendices, Device, Emulation, Engine, Other Usb, Keyboard, Mouse

Appendices

True Emulation is not necessarily required by other USB devices, which is why you will also find two enumerated circuits included (shown in green within the block diagram) alongside the True Emulation feature (shown in blue). This allows those other USB devices to operate at their highest speeds, without any intervention. The enumerated circuits benefit greatly from the USB Hubs that are jointly used with the True Emulation system. Because they interface directly and permanently with each computer, they help to stabilize the dormant links, making errors during enumeration much less likely.

The dual switching arrangement provides further flexibility because the True Emulation and enumerated sections can be switched in unison or independently of each other, as required. Thus, your various peripherals can operate with different computers at the same time.

USB	USB		OTHER USB
KEYBOARD	MOUSE		DEVICE
HOST
CONTROLLER
EMULATION
ENGINE
USB	USB	USB	USB
HUB	HUB	HUB	HUB
PC	PC	PC	PC
1	2	3	4

Figure A-1. True Emulation functional block diagram. The emulated section of the switch is shown in blue and handles only the keyboard and mouse. The green enumerated section of the switch handles other USB devices and also uses the USB hubs to link with the computers.

724-746-5500 blackbox.com Page 39