IHSE USA 461 Series DVXi/ET KVM Extender - Manual (Page 38)

DVXI/ET-XX KVM-EXTENDER
38
USB-Keyboard/USB-Mouse
Your USB-keyboard/USB-mouse does not work
Although we tried to design the devices as transparent as possible, we can’t ensure
that all devices are running. Please ask Technical Support for a list of tested
devices.
Your mouse is ‘stepping’ on your screen
On high resolutions, the amount of data transmitted each second expires the
capability of the data link. Therefore the data have to be reduced before
transmitting. This is done in a first step by a so called RLE (=Run Length
Encoding) algorithm. If this (loss less) compression does not reach the required
amount, frames are dropped: Because of this, ‘stepping’ mouse movements are
seen.
How to solve the problem: Please use a lower resolution or use a desktop
background which is better suitable for compression: Avoid photos for background
or horizontally graduated colors – better use monochrome backgrounds. They allow
higher compression -> higher frame rates.
Your mouse is moving like ‘hanging on a rubber band’
This problem derives from different single problems, which accumulate to a delay
between the true mouse movement and displaying the movement of the mouse
pointer on the screen. Depending to our measurements, a delay of approx. 100-
150msec are recognized as disturbing.
The total delay comes from (time values are approx. values):
•
5 to 15msec for mouse movement and data transmission to CPU
•
50 to 70msec data processing time in the CPU until the changed data
reach the graphic card output connector
•
15 to 45mcec getting the graphic data into the local unit of the
extender system and transmitting to the remote unit (60 to 20fps)
•
10 to 100msec data processing time in the display until the data are
displayed on the screen (where 15msec normally are only reacht by
CRT tubes)
In total there are delay times between 85 and up to 230msec possible, where most
of this delay is NOT caused by the extender system (Extender based delay is 5 to
15msec data transfer to the CPU and 15 to 45msec frame transfer to the remote unit
– in total 20 to 60mesec. Depending to our experiences, even a step from 100msec
delay to 140msec (i.e. by inserting an extender system to a CPU-monitor link) may
cause visible effects.
Please note, that even a monitor directly connected to a CPU has a delay of 70 to
175msec. So (under special conditions) even the bare CPU/monitor link shows this
‘rubber band behaviour’. If you now insert an extender system, the problem may
occur and is (in false) dedicated to the extender system, where it only gives a small
part to the total problem