omx-9021_user_manual操作说明书手册

a serial port,or another device that uses a similar communication0X-9021protocol.Adding inputs or outputs will extend a Switcher's capability.Factors Affecting Qual ity of Results:There are mary fctors affecting the quality of results when signals aretransmitted from a source to an acceptor:Vertical Interval Switcher口Source and acceptor signal handling capability-differentbrands provide different performance levels and the finalresult is largely determined by the component providing theA Word on Video/Audio Switchers:worst performance.Using a source with poor performance willalways result in low quality duplicates.A video/audio Switcher usually switches between severalsources and one or more acceptors.A Switcher that allows severalConnection cables -low quality cables are susceptible toinputs to be connected to several outputs simultaneously is called ainterference,degrade signal quality due to poor matching andMatrix Switcher.Switchers may be of the electronic or mechanicalcause elevated noise levels.They should therefore be of thetype.Most matrices are of the active electronic type,with manybest possible qual ity.crosspoints.Sockets and connectors of the sources and acceptors-so oftenVertical Interval Switching,frequently used in video,ensuresignored,should be of highest quality,since "Zero Ohm"that the transition from one video source to another (such as switchingconnection resistance must be the target.Sockets andbetween two genlocked cameras)is smooth and without interference.connectors must match the required impedance (75 ohms inThe switching and changeover is done during the blanked verticalvideo).Cheap,low quality connectors tend to rust,thusinterval period,when the transition is hidden.causing breaks in the signal path.Genlocked means synchronized so that the color and phaseinformation from each source is identical.Thus switching is done with▣Amplifying circuitry -must have quality performance whenno interference on the screen,no rolling.no color loss and no jumpingthe demanded end result is high linearity,low distortion andon the screen Since the Syncs come with the same timing,all thelow noise operation.information is identical and the transition between one switch and the▣Distance between sources and acceptors-this plays a majorother is smooth.role in the final result.For long distances (over 15 meters)Vertical Interval Switching is needed when recording orbetween sources and acceptors,special measures should betransmitting a video program involving several video sources,as intaken in order to avoid cable losses.These include usinglive broadcast,to ensure clean,undisturbed picture transitions.higher quality cables and,perhaps,adding line amplifiers.Matrices and Switchers may sometimes be RS-232 or RS-485/422 controlled.Each of these options is a way of remotelyInterference from neighboring electrical appliances-thesecontrolling a video/audio device (Switcher,SEG ete.using a PC withcould have an adverse effect on signal quality.Balanc