Changing device modes and workload *MODIFY,F

Function

Several attributes assigned to a functional subsystem (FSS) can be modified, allowing an installation to balance its workload and prevent bottlenecks. For example, if your current workload is heavy, you can have JES3 initiate a converter/interpreter (C/I) FSS by modifying the start value for that FSS from NO to YES.

Use the *MODIFY,F command to change the attributes of the specified FSS.

Use the *MODIFY,F command to increase or decrease the number of C/I service DSPs and JCL statements that can be processed simultaneously in a C/I FSS. Within one command only one parameter can be used for the specified C/I FSS.

Use the *MODIFY,F command to modify the mode associated with an AFP printer. The modify command is valid only when the device is inactive and offline.

The two writer process modes are:

AFP compatibility mode
While running in AFP compatibility mode, JES3 drives the printer directly in the same way that an AFP model 1 is driven. Only line mode data (without embedded format controls) is printed. JES3 ignores JCL format control statements.
FSS mode
While running in FSS mode, an output writer FSS drives the printer. Data that has embedded format controls, as well as line mode data, is printed.

Syntax


>>-+-*MODIFY-+--,--F-------------------------------------------->
   '-*F------'         

>--+-,--D--=--+-devname-----------+--,--M--=--+-COMP-+---------------------------+-><
   |          +-+---+--devnum-----+           '-FSS--'                           |   
   |          | '-⁄-'             |                                              |   
   |          |    .-,-------.    |                                              |   
   |          |    V         |    |                                              |   
   |          '-(----devname-+--)-'                                              |   
   '-,--FSS--=--+-fssname-----------+--+-,--DSPC--=--+-nnn---------------+-----+-'   
                |    .-,-------.    |  |             +-(--,--mmm--)------+     |     
                |    V         |    |  |             '-(--nnn--,--mmm--)-'     |     
                '-(----fssname-+--)-'  +-,--MAST--=--xxxxxxxx------------------+     
                                       +-,--MD--=--msgdest---------------------+     
                                       +-,--P--=--pname------------------------+     
                                       +-,--ST--=--+-Y-+-----------------------+     
                                       |           '-N-'                       |     
                                       +-,--SYS--=--+-sysname----------------+-+     
                                       |            |    .-,-------.         | |     
                                       |            |    V         |         | |     
                                       |            +-(----sysname-+--)------+ |     
                                       |            '-(--sysname--,--NONE--)-' |     
                                       '-,--T--=--+-Y-+------------------------'     
                                                  '-N-'

Parameters

D=devnum or /devnum or devname

Specifies the output device for which the mode is being modified. The device number can be a 3-digit or 4-digit hexadecimal number. A slash (/) preceding the device number is not required. Device numbers can be specified by any of the following formats:

ddd
dddd
/ddd
/dddd

where ddd and dddd represent the device numbers.

M=FSS

Specifies that the device is in FSS mode and is supported by an output writer FSS.

M=COMP

Specifies the device operate in AFP compatibility mode. Devices operating in AFP compatibility mode do not recognize advanced function presentation data stream (AFPDS) format controls.

FSS=(fssname [,fssname]....)

Specifies the name of the FSS being modified.

P=pname

Specifies the name of a procedure library member that contains JCL information for initiating the FSS.

DSPC= nnn or (,mmm) or (nnn,mmm)

Specifies the maximum number of C/I DSPs that can run simultaneously in a CI FSS; nnn specifies the maximum number of batch jobs that can be processed simultaneously and mmm specifies the maximum number of started task and TSO LOGON jobs that can be processed simultaneously. If both counts are specified as zero, the C/I FSS will end.

MD=msgdest

Specifies the JES3 destination class or the MVS™ routing code to be used to route FSS-related messages. The value takes effect the next time the FSS is started. MLG and ALL are incorrect destination classes for this keyword. IBM® reserves certain routing codes for it's use and if specified these codes are ignored.

ST= Y or N

Specifies whether the converter/interpreter FSS is to be started automatically when the local main is connected to the global. If this value is changed from N to Y, JES3 attempts to start the FSS.

SYS=sysname

Specifies the main on which the FSS is to run.

(sysname1,sysname2): Specifies that FSS will run on sysname2 when sysname1 is the global.
(sysname1,NONE): Specifies that FSS will not run when sysname1 is the global.

T= Y or N

Specifies whether JES3 is to end the FSS when the global is ended as a result of a *RETURN command.

MAST= xxxxxxxx

Specifies the maximum number of JCL statements (0 to 99999999) that can be processed simultaneously in the converter/interpreter FSS. If zero is specified, no JCL statement limit is imposed.

Results

Some devices are capable of operating in both FSS or compatibility mode, such as the IBM 3800-3 printer. If you switch device modes, JES3 can alter the process mode definition.

JES3 maintains two process mode lists: one that contains a definition for the primary device mode and one that contains a definition for the alternate device mode. Your system programmer provides an initial value for the primary device mode on the DEVICE initialization statement and JES3 assigns a default process mode value for the alternate device mode. JES3 uses the process mode list associated with the active device mode to determine the process mode definition.

Examples

Change to IATPLB08 the name of the procedure library member that contains JCL information for initiating FSS, WTSUBSYS:

*MODIFY,F,FSS=WTSUBSYS,P=IATPLB08

Change the number of C/I DSPs to run simultaneously in FSS CISUBSYS to 10 for batch jobs and 15 for TSO LOGON jobs:

*F,F,FSS=CISUBSYS,DSPC=(10,15)

Have JES3 initiate the C/I FSS CISUBSYS. (Start value is currently NO and DSP counts are greater than 0):

*F,F,FSS=CISUBSYS,ST=Y

Specify that FSS WTSUBSYS can run on SY1:

*F,F,FSS=WTSUBSYS,SYS=SY1

You do not want FSS WTSUBSYS to end if an *RETURN command is entered:

*F,F,FSS=WTSUBSYS,T=N

Set at 5000 the maximum number of JCL statements that can be processed in C/I FSS CISUBSYS:

*F,F,FSS=CISUBSYS,MAST=5000

Change the destination class of FSS WTSUBSYS messages to ERR:

*F,F,FSS=WTSUBSYS,MD=ERR

Modify the maximum allowable number of C/I DSPs in the C/I FSS, CISUBSYS, to 3 for batch jobs and 5 for started task and TSO LOGON jobs:

*F,F,FSS=CISUBSYS,DSPC=(3,5)

Modify the C/I FSS, CISUBSYS, so that it is not to be started automatically when the main connects:

*F,F,FSS=CISUBSYS,ST=N

Specify that the C/I FSS, CISUBSYS, should run on SY2:

*F,F,FSS=CISUBSYS,SYS=SY2

Use the following JES3 command to switch modes:

If you specify MODE=FSS and PM=PAGE on the DEVICE initialization statement, FSS is the primary device mode and PAGE is the process mode in effect.

However, if you enter:

*MODIFY,F,D=ddd,M=COMP

JES3 makes the alternate process mode list active and uses LINE as the process mode definition. FSS becomes the alternate device mode and PAGE becomes the alternate process mode definition.

Note: You can only update the process mode definition for the device mode that is currently active. If you alter the primary process mode definition, JES3 maintains the updated definition until a JES3 global main restart.