ADDER A.I.M. User Manual page 44

Problem: A.I.M. cannot locate working ALIF units.
There are a few possible causes:
• The ALIF units must be reset back to their zero config IP addresses for A.I.M.
discovery. If you have a working network of ALIF's without A.I.M. and then add A.I.M. to
the network A.I.M. will not discover the ALIFs until they are reset to the zero config IP
addresses.
• This could be caused by Layer 2 Cisco switches that have
(STP) enabled but do not also have portfast enabled on the ports to which ALIF units
are connected. Without portfast enabled, ALIF units will all be assigned the same
zero config IP address at reboot and A.I.M. will only acquire them one at a time on a
random basis.
You can easily tell whether portfast is enabled on a switch that is running STP: When
you plug the link cable from a working ALIF unit into the switch port, check how long
it takes for the port indicator to change from orange to green. If it takes roughly one
second, portfast is on; if it takes roughly thirty seconds then portfast is disabled.
Remedies:
• Ensure that the ALIF units and the A.I.M. server are located within the same subnet.
A.I.M. cannot cross subnet boundaries.
• Manually reset the ALIF units to their zero config IP addresses. Please refer to the ALIF
user guide for details.
• Enable portfast on all switch ports that have ALIF units attached to them or try
temporarily disabling STP on the switches while A.I.M. is attempting to locate ALIF
units.
Problem: The mouse pointer of the ALIF receiver is slow or sluggish when
moved across the screen.
This issue is often related to either using dithering on the video output of one or more
transmitting computers or using VGA-to-DVI video converters.
Dithering is used to improve the perceived quality and color depth of images by diffusing
or altering the color of pixels between video frames. This practice is commonly used
on Apple Mac computers using ATI or Nvidia graphics cards. VGA-to-DVI converters
Spanning Tree Protocol
unwittingly produce a similar issue by creating high levels of pixel background noise.
ALIF units attempt to considerably reduce network traffic by transmitting only the pixels
that change between successive video frames. When dithering is enabled and/or VGA-to-
DVI converters are used, this can have the effect of changing almost every pixel between
each frame, thus forcing the ALIF transmitter to send the whole of every frame: resulting
in greatly increased network traffic and what's perceived as sluggish performance.
Remedies:
• linux Pcs - Check the video settings on the PC. If the Dither video box option is
enabled, disable it.
• Apple Mac with Nvidia graphics - Use the Adder utility for Macs (contact
technical support).
• Apple Mac with ATI graphics - Use the ALIF 2000 series unit with Magic Eye dither
removal feature.
• Windows Pcs - If you suspect these issues with PCs, contact technical support for
assistance.
43