Cantar v1.29 user manual 2004 Sept 28
p.8
Time (a)
One clock, three clocks
Time is the essence in a digital
audio recorder, two types of
times are in use: the «calendar
time» and the «syncing time»
Calendar time
is kept for ever (four years) by an
always active low precision clock which automatically
creates folders in which are stored the audio files of
each working day.
Syncing time
is kept by various clocks which ensure
image, metadata and sound sync
Clock-A
: the internal 1ppm
‘time-of-day clock’
mas-
ter keeps the time with virtually no drift; this time is
used to stamp the sound files to the very same TC
as the one stamped onto the images by cameras and
in metadata-storage devices.
Clock-B:
the internal
‘rec-run clock’
generates a
start of take TC which is two second incremented
over the preceding stop TC (requires a wired or
wireless link from Cantar to cameras & digislates).
Clock-C:
the externally ‘
slaved clock’
ensures that
sound files are stamped by the time generator of the
video camera itself (requires a wired or wireless link
from camera to Cantar).
One Calendar Clock...
The ‘days & hours’ calendar relies upon a medium
precision clock which permanently runs on a lithium
battery (like a watch). Its setup is of primary impor-
tance to the file management system. Its time must
be checked for coherence (±5 minutes) with the
time-zone you are working in. Think about this
when you get off a six-hour flight! The day and time
show on the message panel when the main selector
is on STOP.
To modify the ‘days and hours’ calendar time, go to
the main-selector TECH position and select “System
day” and “System hour”, press OK, a triangle points
to the modifiable element. Using the jog, select the
desired figure, with arrows move on to the next
figure. Press OK to validate.
A
working day
is from about 8 am to 4 am the next
day. If you switch off the batteries after midnight,
Cantar thinks the operator has gone to sleep. But
if your ‘working day’ is continued in the wee hours
after a midnight snack, you would probably not want
it to be considered as a ‘new’ day. That is why Cantar
asks ‘start new day?’, giving you the opportunity to
decline the offer.
The ‘new working day’ is not related to the actual
time of day tracked by the syncing clock; it is only an
interpretation of the ‘human’ day. Thus, if you stop
working at 2am one day, the audio files are still part
of the (technically) ‘previous’ day folder. Conversely
if you want to start a new working day right after
midnight, you only have to switch off the battery and
immediatly switch on, then answer [Yes] to the ‘start
new day’ question. Cantar requests a Yes/No answer,
but since it happens once a day only, this rude beha-
vior remains acceptable.
... and three Syncing Clocks.
At start-up you will no doubt notice a blinking
intc
or
extc
, depending upon the selected working
mode. This means that Cantar is waiting for the
time reference needed to stamp the sound files with
the precision requested to sync cameras and audio
recorders.
Sync clock-A: real time master ‘intc’
The internal sync clock can be initialized many ways:
Calendar init. :
pressing [Shift•JamTC] for more than
two seconds forces the calendar days and hours
into the internal master clock. Stc (system calendar)
shows in the message panel.
If in a panic situation you forget to press [Shift•JamTC],
the calendar days and hours will be used by default and
the blinking
intc
icon will remind you to either ackno-
ledge this choice, or to jam the master clock by one of
three methods below.
LTC jaming :
pressing [JamTC] for more than two
seconds makes a Lemo-5 entered Smpte LTC from
a recorder, camera, etc. jam the Cantar sync clock.
Jtc (LTC jammed) shows in the message panel. If
there is no LTC on the Lemo-5, ‘failed’ shows and the
intc
icon keeps blinking.
ASCII jaming :
used with AatonCode or Arri FIS time
recording film cameras, or video camera recording
free-run TC. The clocks of the camera are set by a
go-between time keeper such as an Aaton OriginC,
an Aaton GMT or an Ambient Clock-It trilevel gene-
rator. Atc (Ascii) shows in the message panel.
Keyboard init. :
when the time must start from an
arbitrary origin such as 01:00:00:00 98-03-24-75
it must be keyed by the operator (available Nov.
2004).
As soon as the
intc
icon no longer blinks Cantar
behaves as a master clock and generates a 1ppm
accurate production timecode from its TCXO, i.e.
eight hour filming /- one frame.
Note: set your Hdd to sleep one minute after STOP.
The power consumption becoming a mere 270mA,
there is no need to power down Cantar during
