GRASS VALLEY JUPITER CM-4400 - VERSION 7.9.0 - 10-2010 User Manual

204 JUPITER CM-4400 Control Module Installation and Operating Manual
Section 5 — The Configurator Application
The Time Standard Table
The Time Standard table is used to identify one or more backup time
sources for use if the time code source fails. Each CM-4400 in the system
must be described (only one entry is required for a redundant pair). See
Time Standard Table Description on
page 205.
Changes made to the Time Standard table do not t
ake effect until you
reboot the CM.
Setting the Time Code Information
Time code is used for short-term, frame-accurate switching. Since NTSC
video signals run at 29.97 frames per second, drop- frame time code accu-
mulates an error of 2.2610 frames per day. This amounts to +75.442 millisec-
onds of drift every 24 hours, a discr
epancy larger than two seconds every
month.
AccuSwitch tracks two time lines, SMPTE time code and an internal
real-
time clock (RTC). The preferred time source is house SMPTE time code.
When a valid time code is not present, the real-time clock will use the
Simple Network Time Protocol (SNTP) to synchronize with the specified
sources in the following order:
1) TCR (Time Code Reader) Host
2) NTP (Network Time Protocol) Host
3) RTC (Real-Time Clock) Host
For example, if the SMPTE time code sour
ce were to fail the CM-4400would
attempt switch to the SNTP source; if that source was not available then the
CM-4400hardware clock would be used, etc.
The real-time clock (RTC) is used to accurately track time long term. This
clock
is synchronized with other sources based on the entries in the Time
Standard table. The real-time clock’s hours, minutes, and seconds will be
synchronized to this time code if the time code is present. If time code is not
present, the SMPTE time line will be synchronized with the real-time clock
(the real-time clock is a backup time line).
AccuSwitch will inhibit adjustments to
the SMPTE time line when the
system is under a load. The time line will only be adjusted when nothing is
happening. The CM-4400 will be synchronized with another CM-4400 con-
nected to a time code reader. This would keep the time within a few milli-
seconds of time code.

GRASS VALLEY JUPITER CM-4400 - VERSION 7.9.0 - 10-2010 Specifications

General

Brand	GRASS VALLEY
Model	JUPITER CM-4400 - VERSION 7.9.0 - 10-2010
Category	Control Systems
Language	English