Instruction manual

ORION LC Installation and Operations Manual
29
Troubleshooting – USB- Keyboard/ Mouse
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.
USB- Mouse makes erratic movements
 With high monitor resolutions, the data volume that can be transferred
may exceed the available bandwidth, so the data throughput must be
reduced. For this, the device uses a RLE compression algorithm. If the
necessary compression factor is not reached, some frame dropping will
occur and the mouse may make erratic movements. Use a lower
resolution or a background which can be compressed better: Please
avoid photo-backgrounds or color gradient – single-colored backgrounds
are optimal and permit the highest possible compression rates and
highest frame rates .
Your USB- Mouse moves like its on “elastic”
This problem is caused by several factors which lead to a time delay
between mouse movement and display on the screen. Contributions to the
total delay consist of (numerical data are approx. values):
 Mouse movement/ transmission of data to the CPU (5 – 15 ms)
 Processing time in the CPU until mouse movement at the graphic output
appears (50 – 70 ms)
 Transmission of the graphic data into the extender-system and
transmission to the Remote Unit (15 – 45 ms)
 Processing time in the graphical output device (15 – 100 ms, where 15 ms are
only reached with CRT tubes)
The majority of the delay, between 85 and 230 ms, is not a consequence of the
extender-system. The extender system is responsible for 5 -15 ms mouse
movement/ transmission to the CPU plus 15 – 45 ms acquiring the graphic data and
transmitting it to the Remote Unit. Our measurements show that time delays greater
than about 100-150 ms become noticeable and bothering. Therefore, if an extender
system increases the mouse signal delay from, say, 100ms to 140ms you may begin
to experience the “elastic” delay problem.
If you use a slow response TFT screen you may already have a total response time
of up to 175 ms, right at the threshold level. The addition of an extender line to such
a system will appear to cause the “elastic” mouse delay problem even though the
extender system is responsible for only a small part of the total problem.
Hint: Use a display with a shorter response time (please note: the response time
indicated by the manufacturer is a measure of how quickly two successive pictures
can be displayed, not how long it takes for a signal from the input interface to reach
the screen). Use a lower resolution or a background which can be compressed
better: Please avoid photo-backgrounds or color gradients – single-colored
backgrounds are optimal and permit highest possible compression rates. If the
transmission needs to drop frames (because the RLE compression algorithm does
not reach the required data reduction) you need to add approx. 17 ms @ 30fps and
approx. 34 ms @ 20fps