All basic schema reference values use representation code IDENT.
| Table 1 - CHANNEL:DIRECTION Reference Values | |||||||||
| Reference Value | Description
| DECREASING
| Channel value strictly decreases as frame number increases.
| INCREASING
| Channel value strictly increases as frame number increases.
| NON-DECREASING
| Channel value does not decrease as frame number increases.
| NON-INCREASING
| Channel value does not increase as frame number increases.
| |
| Table 2 - CHANNEL:FLAGS Reference Values | |||
| Reference Value | Description
| EXPLICIT-SIZE
|
When present, the channel is explicitly sized. In this case
a dimension or aggregate descriptor for the channel will be
found at the beginning of each frame block in which the
channel value occurs. A dimension or aggregate descriptor
consists of a count followed by a standard DIMENSION or
AGGREGATE value, all written using representation code
ULONG only. The descriptor is recorded at the beginning of
the frame block immediately following the last frame num-
ber. If more than one channel is explicitly sized, then
descriptors are written in the same order as the explicitly-
sized channels in the frames.
| When a channel is explicitly-sized, then DIMENSION and AGGREGATE attributes shall be absent from the CHAN- NEL object. Either DIMENSION-LIMIT or AGGRE- GATE-LIMIT but not both shall be present to indicate the the kind of descriptor and its maximum count for any frame in the frame type. ELEMENT-LIMIT shall be present to indicate the maximum number of elements of the channel's value for any frame in the frame type. |
| Table 3 - FRAME:FLAGS Reference Values | |||||||||
| Reference Value | Description
| ENCRYPTED
|
IFLRs associated with the frame type are encrypted if and
only if this value is present.
| INCREASING
|
When present, frame numbers shall increase in the order in
which frames occur, but there may be gaps. The frame num-
ber of the first frame may be any positive integer.
| SEQUENTIAL
|
When present, frame numbers shall increase sequentially
(no gaps) in the order in which frames are written. The
frame number of the first frame may be any positive integer.
| UNORDERED
|
When present, frame numbers may occur in any order.
| Flag values INCREASING, SEQUENTIAL, and UNORDERED are mutually exclusive. If none are present, then SEQUENTIAL is assumed by default. |
There are two reasons for having sequentially-ordered frame numbers. First, it provides an indicator of when records have been lost - a frame number will be observed missing. Second, it allows seeking frames by position without having to count all frames in between.On the other hand, it can be useful to have unordered frames when using an indexing hypergrid for the frame type (see Part 6). Since location on the hypergrid is a function of frame number, unordered frame numbers allow representation of different kinds of "cuts" through the hypergrid, as well as dropouts and other irregularities.
| Table 4 - PROCESS:STATUS Reference Values | |||||||
| Reference Value | Description
| ABORTED
|
The process was aborted.
| COMPLETE
|
The process completed.
| IN-PROGRESS
|
The process began but did not complete.
| |