genlock(7)

NAME
     genlock - genlock capability on IRIS-4D Series machines

DESCRIPTION
     Genlock is the synchronizing of two video outputs, such that the
     horizontal and vertical sync signals are aligned. For genlock to be
     possible, the two video outputs must be running the same video format.
     All IRIS-4D Series graphics systems have some genlock capability.

     A graphics pipe normally has on it a clock source, such as a crystal,
     that is used to generate internal timings. To genlock a graphics pipe,
     you must supply a suitable external clock; you must then inform the
     software that it is to use the supplied clock instead of its internal
     default.

     Genlock is controlled by the setmon(1G) command and the setmonitor(3G)
     IrisGL function call. To enable or disable genlock, you must use one of
     these. For a full description of the various parameters available please
     consult those man pages.

     When genlocking two IRIS-4D Series machines together, you should
     designate one system as the `master' and the other as the `slave'.  The
     master system will run normally and use its internal crystal to generate
     its sync signal. The slave system will take the sync signal from the
     first system and use it; the call to setmon(1G) or setmonitor(3G) should
     only be done on the slave system. To route the sync signal would
     typically require a coaxial cable from the `Sync Output' jack of the
     master system to the `Genlock Input' jack of the slave system. Also, this
     signal should usually be terminated at the destination end with a 75-ohm
     resistor.

     If more than two graphics systems are to be locked together, you must
     still designate one system as the `master'; all other systems are
     `slaves'. Care must be taken in this setup to correctly route the sync
     from the master to all of the slaves; this should normally be done in
     daisy-chain fashion. Note that this connection must be terminated only
     once, at the last slave in the chain.

NOTE
     In some multi-screen stereo applications it is desirable to genlock
     stereo screens together.  Care must be taken to ensure that right-eye
     views are locked together.  For some older stereo formats, this may
     require several attemps; the system may lock the left eye of one screen
     to the right eye of the other. If this occurs, turn genlock off and try
     the genlock again.

     Removing and reconnecting the sync signal from the sync input is not
     suggested, as this may cause problems with the hardware. Genlock should
     always be turned off via setmon(1G) or setmonitor(3G) before connecting
     or disconnecting the sync signal.
     In a IRIS-4D system with multiple graphics pipelines, these pipelines are
     not automatically genlocked; they run completely independantly, exactly
     as if they were in different systems. If it is desired to run the
     graphics pipes genlocked together, this must be done by the user as
     described above.

     In general, the input sync reference signal must be identical to the
     output sync signal for that format; in other words, you can generally
     only lock together identical video formats.

SEE ALSO
     setmon(1G), setmonitor(3G)