User manual

Computer Gateway User Manual 4-98 5/96
4.8.2
Sixteen-Character Tagname Form
Header information: Word 1—Transaction Code = 151
Word 2—Number of Words = 14 plus size of the data table
Word 5—CG Identifier = 2
Message format: Words 1..8—ACIDP name or blank (16 ASCII characters)
Words 9..13—reserved for future use
Word 14—return status (integer)
0=normal return
4=begin period is invalid
5=complete with errors
6=end period is invalid
7=history type invalid or data access failed
9=HM rejects the request for history
10=the DDT was empty
13=begin-end periods are invalid
14=the requested number of samples exceed
the size of the return buffer
15=ACIDP not in the correct EXECSTAT
16=ACIDP name is invalid
33=data type requested in the DDT is invalid
35=referenced DDT is not of type "history"
37=referenced DDT has duplicate data types
39=referenced DDT contains too many
point.parameters
40=number of words in the request header is
incorrect
Word 15—start of history data values
Data format: Each point/parameter's values for snapshots and averages are
contained within variable length records that depend on history
type. Each record begins with a 2-word record header, followed
by a number of subrecords of either 5, 10, or 11 words each.
The record header format is
Word 1 data access status (integer)—See the Messages Directory
Word 2 number of subrecords for this point/parameter (integer)
If the Data Access Status Code is not 4, 5, 6 or 8, the number of
subrecords is zero. When the number of subrecords is zero, only
the header words are used.
For Snapshots (history type = 0, 9, 10, or 11), each subrecord is
five words long, and conforms to one of three forms. Content of
each subrecord is established by its value type (word 1 of each
subrecord). See paragraph 4.8.2.1.
Form 1
Word 1 =0 (integer)—real process data value
Words 2..3 process value (real)
Words 4..5 timestamp (unsigned 32-bit integer)