Black Box ServSwitch SW721AE-R2, Руководство пользователя

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4.3.7 S
ET
K
EYBOARD
M
ODE
Keyboard “modes” are electrical signaling protocols that determine how a powered
CPU and keyboard interact. A CPU and keyboard must use the same mode in
order to work with each other. Of the three standard keyboard modes currently in
use, mode number 2 is the one used by the vast majority of CPUs. It is also the
default state of all 101-key and PS/2 keyboards. Mode 1 is used primarily by certain
PS/2 CPUs. Mode 3 is used by certain specialized servers. The ServSwitch supports
all three of these modes: As it receives signals from the keyboard, it sends them to
the currently selected CPU by emulating a keyboard of the appropriate mode for
that CPU; as it receives signals for the keyboard from the currently selected or
scanned CPU, it sends them to the keyboard by emulating a CPU of the
appropriate mode.
Most CPUs that use keyboard mode 1 or 3 send a “mode command” to the
keyboard at power-up, to put the keyboard in the proper mode. ServSwitches can
use these commands to automatically detect each such CPU’s keyboard mode
when you turn on the CPU after it has been cabled to the switch.
When they detect the mode, 2- and 4-port units automatically save it to NVRAM, so
that if they are turned OFF they will remember it when they are turned ON again.
The ServSwitch can’t detect the CPU’s keyboard mode if your CPU doesn’t send
“mode commands” (most CPUs that use mode 2 fall into this category) or the CPU
is already ON when you connect it to the ServSwitch (it shouldn’t be). In these
situations, the ServSwitch tries to use the keyboard-mode setting stored in its
nonvolatile memory for that port. The factory-default is mode 2 for all ports. Send
the Set Keyboard Mode command to change the keyboard mode for a port if:
• the CPU on that port uses mode 1 or 3,
• it uses mode 2, but the default setting of the port you want to connect it to has
been changed, or
• you don’t know which mode the CPU uses or the port is set for, but the
keyboard’s behavior makes you suspect that the port’s setting is wrong.
To set the keyboard mode of the currently selected port on a ServSwitch, press and
release the left Control Key, type [M], and press the numeral key of the mode
number ([1], [2], or [3]). After you enter this command, enter the Keep Settings
command to save the mode setting in NVRAM, so that the new setting becomes the
default value (preserved during power-down and reloaded at power-up).
CHAPTER 4: Operation