CA Dynam for VSE User Guide

Using the Console Alarm Facility
IBM does not provide a standard facility for protection of shared tape drives in
a multiple system environment. With DTLOCK, an external LOCK option record
is issued whenever CA Dynam/T is ready to access a tape drive. This assures
that the tape drive is not in use by CA Dynam/T from another CPU. If it is in
use, the drive is bypassed during AVR or considered NOT AVAILABLE if the
operator attempts to override AVR. The LOCK is released when CA Dynam/T
decides not to use the drive or processing for the file is completed.
The standard VSE LOCK option record (available on VSE r2 and above) is used,
so abnormal termination of any kind results in the LOCK being cleared by endof-job
routines automatically. In addition, the AR command interface provides
for operator-controlled locking or unlocking of the tape drive.
Using the Console Alarm Facility
The console alarm rings whenever a message requiring operator action or
response is issued (-A or -D messages) if you specify ALARM(YES) in the
DYNAM/T option record. This is especially useful if the console is unattended
for periods of time.
Chapter 2: Maintaining Tape Files 2–85