User manual

Computer Gateway User Manual 4-112 5/96
4.10.2
Word 29—Ending record requested
(Words 28 and 29 are not used when Word 27 = 0)
Words 30—User supplied time-out in seconds.
The valid values are 1 to 1800.
A value outside this range sets a default of 60.
Words 31..40—Reserved for response data
4.10.2.2 Read LCN File Response
Header information: Word 1—Transaction Code = 63
Word 2—Number of Words = 40 + data size
Word 5—CG Identifier = 2
Message format: Words 1..10—Request echo
Word 11—Return status 0 = normal
Word 12—Return substatus 0 = normal
Words 13..29—Request echo
Word 30—Total number of records in file*
Word 31—Number of records in this transmission
Word 32—First record number of this transmission
Word 33—Last record number of this transmission
Word 34—Record size*
Word 35—File type* 0 = contiguous, 1 = linked
Word 36—File block size* 4 to 45 for linked file
0 for contiguous file
Word 37—Number of blocks used*
Word 38—File configuration* 0 to 511
Word 39—File revision* 0 to 63
Word 40—Write access code* 0 = unprotected
Data information: Words 1..32—File descriptor* (ASCII characters)
Words 33..5792—File data
4.10.3 Write LCN File
This request/response pair writes a single file and its attributes from the host to a volume on
the LCN's HM. Contiguous or linked files can be transferred.
Record size is affected by file type.
• Contiguous files have a fixed record size of 256 bytes.
• Linked files can have either a fixed or a variable record size.
- The record size common to all records of a fixed-length linked file is specified in
word 28 of the request message.
- The record size of each variable-length record is found in the first two bytes of the
record itself.
The maximum file data size in a single transmittal is 5760 words, thus several transmission
request/response pairs can be required to transfer a complete file. Partial files can be
transmitted, but a record is always complete within one transmission.