40
SERVSWITCH WIZARD PRO
5.10 RS-232 Control
There is yet one more way to select channels on the ServSwitch Wizard Pro:
through its RS-232 serial port. (This is a proprietarily pinned DB15 connector;
see
Section A.3
of
Appendix A
for more information.) The normal use of this
connector is as the attachment point for the Switch’s optional Remote-Control
Module, but by using an adapter you can connect a different RS-232 device to it.
To select a channel through this port, the data rate and format of the sending
device must be set to 1200 bps, 8 data bits, no parity, and 1 stop bit. No
handshaking (flow control) is used by the ServSwitch Wizard Pro.
Simply send the ASCII character for the channel which needs to be selected:
ASCII “1” (31 hex, 49 decimal) will select channel 1, ASCII “2” (32 hex,
50 decimal) will select channel 2, and so on.
5.11 Cascading ServSwitch Wizard Pros
Multiple ServSwitch Wizard Pros can be cascaded (connected together in a one-to-
many scheme) in order to increase the maximum number of available CPU ports
in your KVM-switching system. You can include ServSwitch Wizards and ServSwitch
Duos in such cascades as well. (Note that
each
Switch in a cascade
must
be powered
through a power supply and
not
from the keyboard interface.) This can be
particularly useful where clusters of computers are located some distance from
each other, because each Switch unit acts as a kind of signal booster or repeater
and can be as much as 100 feet (30 m) away from the other Switches in the system.
To select channels in cascaded systems, you will need to either send hotkey
commands from the master Switch’s keyboard (see the “{Hotkeys} + {Channel
Address}” paragraph in
Section 5.5
) or select your desired channel from the
Switch’s on-screen menu (see
Section 5.6
). Most people find using the menu more
convenient, because scrolling through and selecting computer names from the
menu is usually much easier than trying to remember and type in channel
addresses.
Though it’s theoretically possible to cascade ServSwitch Wizard Pros to four, five,
or more “layers,” we recommend that you limit your setup to three, because the
channel addresses for CPU ports on Switches beyond the third layer can be too
long to be entered in the menu.
For an example of hotkey switching, consider a situation in which two ServSwitch
Wizard Pro units, unit “A” and unit “B,” are connected together as shown in
Figure 5-1 on page 42. To select the computer attached to port 3 on ServSwitch
Wizard Pro “B,” you would press and hold down the hotkeys, then press and
