Section 6.4 - ABS setting
6-2
3) When the tape is at the time you want to make
the “zero” point, press the CAPTURE key [29].
The current time value from the first DTRS unit
will be displayed on the LOCATE TIME/VALUE
display [15].
4) Press the STR key [17].
The MEMORY NO. display [14] wil l st ar t t o flash.
5) Press the numeric keypad’s 0 key, and then
press the ENTER/LOAD key [20] to enter the
current time into the
00
location memory.
The TAPE TIM E display will now show
00:00:00:00
, showing that it is now at zero,
relative to the time you have just captured.
If the display shows something other than
00:00:00:00
, this means that the tape is now at
a position other than the point where you captured
the time (i.e. the tape was play i ng or recording).
All times now are relative to this time. Any loca-
tions will now be shown on the TAPE TIME dis-
play relative to the new
00
memory. For example ,
if the relative “zero point” is set to
00:30:00:00
, when the tape is at the absolute
location of
00:45:00:00
, the value shown on
the TAPE TIME display will be
00:15:00:00
(45 – 30). However, even though the value shown
on the TAPE TIME display ch anges, neither the
actual tape position nor values shown on the
LOCATE TIME/VALUE display are affected.
A minus value is shown on the displays either
with a leading minus sign (
–
) on the TAP E TI ME
display, or with a leading period (
.
) on the
LOCATE TIME/VALUE display.
6.3.1 “Return-to-zero”
Since the RC-898 works on time-based, rather
than counter-based, references, there is no dedi-
cated “RTZ” control. However, you can return to
the zero point using the following procedure:
1) Press the RCL key [18].
The MEMORY NO. indicator will start to flash.
2) Press the 0 key on the numeric keypad,
followed by ENTER/LOAD.
The LOCATE TIME/VALUE display will now
show the actual time value of the “zero point”.
3) Press the LOC key [41].
The tape will return to the nominal “zero point”
and the TAPE TIM E display will show
00:00:00:00
.
6.4 ABS settingThe ABS setting allows you to use the subcode on
the servo track of the DTRS unit as the time refer-
ence of the RC-898. Usually, this starts at
00:00:00:00
, and continues for the length of
the tape.
However, there are some options available with
the ABS mode, which increase the flexibility of
the system. These are described in 8.1.2, “Synthe-
sizing timecode from ABS times”, and allow you
to start with an offset, etc. when synsthesizing
timecode.
6.4.1 A note on ABS frame rate
When ABS is selected, the number of frames per
second is different from that in any timecode
mode. For details of setting SMPTE/EBU frame
rates, see 8.1.3, “Selecting a timecode type”.
Timecode (whether SMPTE or EBU) contains a
fixed number of frames per second. However, the
ABS method of timing works in a slightly differ-
ent way.
In three seconds of time, there are 100 frames.
These frames are allocated as follows:
This pattern is repeated every three seconds, as
you will notice when you set fra me values using
the menu system in ABS mode. When multiple
DTRS units are connected together in DTRS sync
mode, the master unit always outputs ABS tim-
ings to the slave unit(s).
6.4.2 Selecting Time Mode
Each DTRS unit in the chain capable of
using timecode (i.e. DA-98 and DA-88/SY-88
units) can be changed to use either timecode or
ABS timing.
00:00:00:00 00:45:00:00
.00:30:00:00
TAPE TIME display
Relative settings
00:00:00:00
Absolute settings
New
“zero”
point
00:15:00:00
Second Number of
frames Maximum frame
value displayed
00 – 01 33 32
01 – 02 33 32
02 – 03 34 33
98 88