User manual

KRAMER: SIMPLE CREATIVE TECHNOLOGY

Solutions to Common Problems

Problem:

Serial communication doesn’t work correctly.

Solution:

Are the serial devices connected properly? Are the serial

parameters correct for source/destination devices?

Are the serial cables terminated correctly? If a null-modem cable

is used, it must be placed at the receiver end.

When using RS-232 transmitters or receivers in daisy chains, CAT

5 switches, or CAT 5 distribution amps, the serial signal is a

unidirectionally broadcast mode only. In this mode, all other

Cobra CAT 5 Video System devices must be the simplex serial

type. For assistance, contact Technical Support.

See Appendix E for Serial board settings. External switch for last

unit in daisy chain.

Problem:

“Green shift” or “green washout” on multimedia signals.

Solution:

The standard video/serial model is designed to function with DC

coupled signals in which the black level is referenced to 0 volts.

Nearly all VGA cards function this way.

Some media servers, however, provide AC coupled signals and

can cause a green color shift in the video. This is a result of the

sync clamping on the red and blue channels of the video/serial

model.

For five-component (RGB/H&V) AC coupled video, the Cobra

CAT 5 Video System T2 Universal transmitter has been designed

with full DC restoration capability.