CA Dynam for VSE User Guide

Using CA Dynam/T
SELECT TAPE-FILE ASSIGN TO SYS010-UT-3420-S-MASTER.
SELECT TAPE-OUT ASSIGN TO SYS011-UT-3420-S-MASTER.
Both files are referred to as MASTER, because of the above COBOL
statements. A second OPEN results in the file being treated as uncontrolled,
because CA Dynam/T requires a separate TLBL for each controlled file.
Both files can be controlled if you use the dynamic file name modification
option on the first of the two TLBLs with the file name MASTER:
// TLBL MASTER,'DSN,A'
// TLBL MASTER,'DSN'
or
// TLBL MASTER,'DSN',,,,,,64
// TLBL MASTER,'DSN'
Suppose the logical unit for the first of the two files to be opened was SYS010.
At OPEN, CA Dynam/T would change the file name to SYS0010 in the program
and on the label track.
Note that if you use the DROP option in conjunction with MODIFY, successive
label records (TLBLs) must use the modified file name (in this case, SYS0010).
Tape Reel Length Specification
CA Dynam/T lets you specify the size of tape reels for specific data sets. This
maximizes your magnetic tape resources. You can indicate tape reel length in
any one of the following ways:
• In the Catalog as an attribute of the data set
• As an alphabetic TLBL option in the file-ID field
CA Dynam/T provides six length codes (XS, S, MS, M, ML, L) ranging from
extra short to long. They allow for data sets of various lengths.
The chart below details the permitted length specifications, as defined to the
Catalog using the DYNCAT DEFINE statement.
This DYNCAT DEFINE
Statement
DEFINE 'ERROR FILE' NGEN=2
LENGTH=XS
DEFINE 'TRANS FILE' NGEN=3
LENGTH=S
Establishes This Tape Length
extra short (200 ft.)
short (400 ft.)
Chapter 2: Maintaining Tape Files 2–39