Grass Valley UniConfi NVISION Series v.1.3 - Manual (Page 83)

UniConfig Configuration Application • User’s Guide 71
9. Managing Switch Point Settings
A “switch point” is a point in time in which an output is switched from the current source to a new
source. Different video and audio formats require different switch points to prevent data or picture
disturbances. UniConfig enables you to set switch point parameters for individual outputs. Switch
points are initially set up as part of configuring a router.
Switch points are managed through the ‘Switch Point Setup’ window.
Reference information for video and audio signals is through reference connections housed on the
router. For video reference signals, there are two connections labeled ‘VIDEO REF’. Both video
reference connections can reference the same signal or each connection can reference a unique sig-
nal. For audio reference signals, there are two connections labeled ‘AES REF’. One or both con-
nections are connected to a stable source of AES3 at a sample rate of 48
kHz. If both reference
connections are connected, one acts as a backup, automatically providing a reference signal should
an AES reference source fail. For more information, see the router User’s Guide.
This section discusses how to set up and manage switch point settings for routers. For information
on setting up EC9535 GSC Node Bus Converter switch points, see
Setting Up EC9535 Switch
Points on page 123.
About Video Signal Fields and Frames
Video signals are comprised of a series of still images presented sequentially giving the impression
of movement. One complete set of still images on a video screen is called a frame.
Depending on the video equipment, still images are “painted” on screens using interlaced or pro-
gressive video techniques. For interlaced video, a frame is composed of two fields, FIELD1 and
FIELD2. Each frame is divided into 525 scan lines. Because a field is one-half a frame, each field is
composed of 262.5 scan lines. Scan lines start at the top of the screen and “paint” horizontally
across the screen until the bottom of the screen is reached. For interlaced video, to paint an entire
frame, first FIELD1 paints all the odd scan lines and then FIELD2 paints all the even scan lines.
For NTSC interlaced video, there are 30 frames per second and 60 fields per second. For NTSC
progressive video, there are only frames, or put another way, frames and fields are the same, so
there are 60 frames per second.
Depending on the router type, UniConfig enables you to switch video signals on a frame or a field:
See How to Select Switch Point Settings for the NV5100MC or NV5128 Router on page 73.
See How to Select Switchpoint Settings for the NV7256 and NV7256-Plus Router on page 75.
See How to Select Switch Point Settings for the NV7512 Router on page 77.
Note In UniConfig, all routers have a ‘Switch Point Setup’ window except NV5256.
The NV5256 routes only machine control signals, which do not have a config-
urable switch point.