User guide

32 CATx KVM Extender Local Hubs
Appendix B: Audio/Serial Ports: Operation &
Multi-Port Configuration
This appendix describes audio & serial interface operation for:
• SDRK/6S and SDRK/6SD
• SDRK/6A and SDRK/6AD
Please note that on dual access Local Hubs, the serial link remains active during
a Private Mode session but audio transmissions are stopped.
Serial Interface Setup and Operation
Serial only systems SDRK/6S and SDRK/6SD
Baud Rate
With serial-only systems, you can set the baud rate for a serial extension to
9600bps or 19200bps at the Remote Unit. Refer to the manual supplied with
your Remote Unit for more information.
You can override this setting and fix the baud rate at 1200bps using a jumper on
the serial daughterboard in the Local Hub. You may want to use this baud rate
to extend a mouse device such as an industrial trackball.
In most cases, we recommend that you use PS/2 mouse devices with your
extender system. If you have a PC that does not have a PS/2 mouse port:
• Plug a PS/2 mouse into the Remote Unit
• Use an Mdapt (PS/2) Serial Mouse Converter to connect the PC to your
Local Unit.
The drivers supplied with certain Wacom Graphics Tablets dynamically alter
the baud rate and cannot be used with an SDRK Extender system. There is a
version of the driver available with a fixed baud rate. Please contact Technical
Support for more information.
To change the baud rate to 1200bps:
1. Remove the Local Hub’s top cover by unfastening the five retaining screws.
2. Lift of the top cover. There are six serial daughter boards for each port in
the Local Hub. Locate the Baud jumper posts on the appropriate serial
daughter board (see Figure 10).
The circuit board has several jumper blocks in addition to
those shown in Figure 10. Do not adjust any of these
settings, as you will cause the extender system to operate
incorrectly.