. . DISPLAY 12E22bl ,TAPE 1 IALL 1 ENABLE L J displays the status of the applicable VM/370 Monitor variables
and the status of the internal trace table. SPOOL is the
default operand. Regardless of the SPOOL, TAPE, or ALL
operand selected, each class of MONITOR CALL and its current
enabled/disabled state is listed on the If SPOOL is requested, the automatic monitoring specifications
are listed on the terminal, including whether or not automatic
monitoring has been requested, its start and stop times, the
number of monitor buffers to be used, the userid of the
virtual machine to receive the spool file, the spool
record limit and class, and which monitor classes are
enabled.
file
to be
If automatic monitoring is already in progress, the spool file
number is given together with the number of monitor buffer
records already written to it.
If the TAPE option is requested, only the status of monitor
classes and the CPTRACE table is indicated.
If ALL is specified, a combination of SPOOL and TAPE responses
are shown on the terminal. PERForm RESPonse SCHedule USER INSTsim DAStap SEEKs SYSprof enables the specified classes of MONITOR successful completion of this command creates a
control register 8. The function of each class
in the section "Implemented Classes."
CALL. Each
new mask for
is described
The effect of the MONITOR ENABLE command depends upon whether
data collection is active or inactive when the command is
issued. If data collection is active (MONITOR START has been
issued), the new mask is moved directly into control register
8, replacing the previous mask, and the new mask takes effect
immediately. Collection then continues with the classes just
entered. If data collection is not active at the time the
command is issued, the mask is saved until the MONITOR START command is issued. If a MONITOR START command is issued
without a preceding MONITOR ENABLE, the SYSMON class
specifications are used. Any mask stays in effect only until
the next MONITOR STOP command. Part 2. Control program (CP) 113

Restrictions exist on issuing the MONITOR ENAELE command while
the VM/370 Monitor is collecting and recording data.
Every MONITOR ENABLE command yields a new mask. Thus, for
example, if PERFORM and USER classes are currently being
collected, and you enter MONITOR ENABLE INSTSI!, then PERFORM and USER classes are stopped and INSTSI! is started.
The DASTAP operand in the MONITOR ENABLE command must be
specified prior to the MONITOR START TAPE command. DASTAP may be disabled at any time by respecifying the MONITOR ENABLE
command with DASTAP absent from the class list.
The SYSPROF class cannot be activated unless both the DASTAP and SCHEDULE classes are also active.
If data collection is in progress when you issue a MONITOR ENABLE command and an error occurs in the command line during
processing, no change is made to the status.
Unrecognizable keywords, conflicting or operands
generate appropriately different error messages.
Due to the potential security exposure that exists with
collecting terminal input and output data, the RESPONSE class
of data collection does not occur unless the system programmer sets the TRACE(1) bit in the LOCAL COPY file to a 1 and
reassembles the CP module DMKMCC. If this is not done, the RESPONSE class is considered an invalid operand of the MONITOR ENABLE command.
r , I INTERVAL nnnnn ISECI nn IMINI L J specifies the time interval to be used for the three timer driven data collection classes: PERFORM, USER, and DASTAP. The value specified by nnnnn is the number of seconds or
minutes between data collections. If no interval is specified
'on the MONITOR INTERVAL command, an error message is
generated. If you give an interval but enter neither SEC nor MIN, the default is SEC. The maximum allowatle interval is 9
hours (540 minutes or 32,400 seconds). The minimum is 30 seconds.
If the MONITOR INTERVAL command is not issued, the default
interval is 60 seconds. The MONITOR INTERVAL command can be
issued at any time; however, if data collection is already in
progress, the new interval does not take effect until the
current interval has elapsed.
nn specifies how frequently the VM/370 Monitor is to sample
channel status, control unit status, and device status for
the DASTAP class. The nn parameter specifies only seconds,
has a minimum value of 1, a maximum value of 99, and a
default value of 2. The amount of time specified by nn
must be less than the amount of time specified by nnnnn.
The value of nn and the value of nnnnn work together in the
following way. The VM/370 Monitor accumulates channel
status, control unit status, and device status in a buffer.
The value of nn determines the frequency of accumulation;
the value of nnnnn determines how frequently the buffer is
114 IBM VM/370 System programmer's Guide