|
DCB
subparameters |
Access method |
Description
of subparameters |
---|
B
D
A
M
|
B
P
A
M
|
B
S
A
M
|
B
T
A
M
|
E
X
C
P
|
G
A
M
|
Q
S
A
M
|
T
C
A
M
|
---|
BFALN |
X |
X |
X |
|
X |
|
X |
|
BFALN={F|D} Specifies that each buffer starts either on a word boundary that
is not also a doubleword boundary or on a doubleword boundary. If
both BFALN and BFTEK are specified, they must be specified from the
same source.
Default: D (doubleword)
Note: Do not
code the BFALN subparameter with DCB subparameter GNCP, or with DD
parameters DDNAME or QNAME.
|
BFTEK |
X |
|
X |
X |
|
|
X |
|
BDAM and BSAM: BFTEK=R - R
- Specifies that the data set is being created for or contains variable-length
spanned records. Do not specify R for a PDSE.
BTAM: BFTEK=D - D
- Specifies that dynamic buffering is to be used in the processing
program; if dynamic buffering is specified, a buffer pool also must
be defined.
QSAM: BFTEK={S|A} - S
- Specifies simple buffering (default). Simple buffering may be
coded at any time for QSAM files.
- A
- Specifies locate mode logical record interface for spanned records.
QSAM obtains a logical record area and assembles the physical record
segments of a spanned record into that logical record area. This forms
a complete logical record before pointing the user to it.
- This parameter value may be specified only for RECFM=VS or RECFM=VBS
files; if specified without RECFM=VS|VBS, the specification is ignored.
- Locate mode must be used together with this parameter value.
Note: If you use locate mode on a RECFM=VS|VBS file and BFTEK=A is not specified, the results may include processing the segments
of a spanned record as separate records, issuance of system completion
(abend) code X'002' with reason code X'04', or other
unpredictable results.
- If you specify BFTEK=A with move mode, a system completion (abend)
code X'013' with reason code X'5C' is issued.
For information about the locate and move modes
in the DCB subparameters BFTEK and VBS, see z/OS DFSMS Macro Instructions for Data Sets.
If you specify both BFALN and BFTEK, you must
specify them from the same source.
Note: Do not code the BFTEK
subparameter with DCB subparameter GNCP, or with DD parameters DDNAME
or QNAME.
Note: For compatibility purposes with previous
operating systems, the system accepts BFTEK=E.
|
BLKSIZE |
X |
X |
X |
|
X |
|
X |
X |
BLKSIZE={value|valueK|valueM|valueG} Specifies the maximum length, in bytes, of a block.
- value
- Specifies the maximum length of a block. The number you specify
for BLKSIZE depends on the device type and the record format for the
data set. The maximum is 32,760 for DASD data sets and 2,147,483,648
for tape, except for data sets on magnetic tape with ISO/ANSI/FIPS
labels, where the minimum value for BLKSIZE is 18 bytes and the maximum
is 2048 bytes. (To allow a value greater than 2048, use installation
exit routine IFG0193G, described in z/OS DFSMS Installation Exits.)
- valueK
- Specifies the maximum length, in kilobytes, of a block. (1 kilobyte
= 1024 bytes.) The maximum is 2097152. If 2097152K is coded, the block
size assigned will be the maximum: 2,147,483,648.
- valueM
- Specifies the maximum length, in megabytes, of a block. (1 megabyte
= 1024 kilobytes.) The maximum is 2048. If 2048M is coded, the block
size assigned will be the maximum: 2,147,483,648.
- valueG
- Specifies the maximum length, in gigabytes, of a block. (1 gigabyte
= 1024 megabytes.) The maximum is 2G. If 2G is coded, the block size
assigned will be the maximum: 2,147,483,648.
If you code the BLKSIZE subparameter in the DCB
macro instruction or on a DD statement that defines an existing data
set with standard labels, the DCB BLKSIZE overrides the block size
specified in the label. BLKSIZE can be coded but will have no effect
on EXCP processing.
The number you specify for BLKSIZE directly
affects the amount of space obtained for data sets allocated in records,
and for data sets allocated in blocks where the block length (blklgth)
is zero.
Default: If you do not code BLKSIZE, the system can,
under certain conditions, determine an optimum block size for the
data. For detailed information about system-determined block size,
see z/OS DFSMS Using Data Sets.
Note: Do not code the BLKSIZE subparameter with the BUFSIZE subparameter.
|
BUFIN |
|
|
|
|
|
|
|
X |
BUFIN=buffers Specifies the number of buffers to be assigned initially for receiving
operations for each line in the line group. The combined BUFIN and
BUFOUT values must not be greater than the number of buffers in the
buffer pool for this line group (not including those for disk activity
only).
Default: 1
Note: Do not code the BUFIN subparameter
with DCB subparameter BUFNO, or DD parameters DDNAME, QNAME.
|
BUFL |
X |
X |
X |
|
X |
|
X |
X |
BUFL=bytes Specifies the length, in bytes, of each buffer in the buffer pool.
The maximum is 32,760.
Note: Do not code the BUFL subparameter
with DD parameter DDNAME.
|
BUFMAX |
|
|
|
|
|
|
|
X |
BUFMAX=buffers Specifies the maximum number of buffers to be allocated to a line
at one time. Number must be 2 through 15 and must be equal to or
greater than the larger of the numbers specified by the BUFIN and
BUFOUT subparameters.
Default: 2
Note: Do not code
the BUFMAX subparameter with DCB subparameter NCP, or DD parameters
DDNAME, QNAME.
|
BUFNO |
X |
X |
X |
X |
X |
|
X |
|
BUFNO=buffers Specifies the number of buffers to be assigned to the DCB. The maximum
normally is 255, but can be less because of the size of the region.
Note: Do not code the BUFNO subparameter with DCB subparameters
BUFIN, BUFOUT, or DD parameter QNAME.
|
BUFOFF |
|
|
X |
|
|
|
X |
|
BUFOFF={n|L} - n
- Specifies the length, in bytes, of the block prefix used with
an ASCII tape data set. For input, n can be 0 through 99. For output,
n must be 0 for writing an output data set with fixed-length or undefined-length
records.
- L
- Specifies that the block prefix is 4 bytes and contains the block
length. BUFOFF=L is valid only with RECFM=D. For output, only BUFOFF=L
is valid.
Note: Do not code the BUFOFF subparameter with
DD parameters DDNAME, QNAME.
|
BUFOUT |
|
|
|
|
|
|
|
X |
BUFOUT=buffers Specifies the number of buffers to be assigned initially for sending
operations for each line in the line group. The combined number of
BUFIN and BUFOUT values must not be greater than the number of buffers
in the buffer pool for this line group (not including those for disk
activity only) and cannot exceed 15.
Default: 2
Note: Do not code the BUFOUT subparameter with DCB subparameter BUFNO,
or DD parameter DDNAME.
|
BUFSIZE |
|
|
|
|
|
|
|
X |
BUFSIZE=bytes Specifies the length, in bytes, of each of the buffers to be used
for all lines in a particular line group. Length must be 31 through
65535 bytes.
Note: Do not code the BUFSIZE subparameter with
DCB subparameter BLKSIZE, or DD parameters DDNAME, QNAME.
|
CPRI |
|
|
|
|
|
|
|
X |
CPRI={R|E|S} Specifies the relative transmission priority assigned to the lines
in this line group. - R
- Specifies that processor receiving has priority over processor
sending.
- E
- Specifies that receiving and sending have equal priority.
- S
- Specifies that processor sending has priority over processor receiving.
Note: Do not code the CPRI subparameter with
DCB subparameter THRESH, or DD parameters DDNAME, OUTLIM, QNAME.
|
CYLOFL |
|
|
|
|
|
|
|
|
CYLOFL=tracks Specifies the number of tracks on each cylinder to hold the records
that overflow from other tracks on that cylinder. The maximum is 99.
Specify CYLOFL only when OPTCD=Y.
Note: Do not code the CYLOFL
subparameter with DCB subparameter RESERVE, or DD parameters DDNAME,
FCB, QNAME, UCS.
|
DEN |
|
|
X |
|
X |
|
X |
|
DEN={1|2|3|4} Specifies the magnetic density, in number of bits-per-inch, used
to write a magnetic tape data set. DEN 7-track tape 9-track tape
1 556 -
2 800 800 (NRZI)
3 - 1600 (PE)
4 - 6250 (GCR)
- NRZI
- Non-return-to-zero inverted recording mode.
- PE
- Phase encoded recording mode.
- GCR
- Group coded recording mode.
- Default:
- 800 bpi assumed for 7-track tape and 9-track without dual density.
1600 bpi assumed for 9-track with dual density or phase-encoded drives.
6250 bpi assumed for 9-track with 6250/1600 bpi dual density
or group coded recording tape.
Note: Do not code the DEN subparameter with
DD parameters DDNAME, QNAME.
|
DIAGNS |
X |
X |
X |
X |
X |
X |
X |
|
DIAGNS=TRACE Specifies the OPEN/CLOSE/EOV trace option, which gives a module-by-module trace of
OPEN/CLOSE/EOV’s work area and the DCB. If the generalized trace
facility (GTF) is not running and tracing user events, DIAGNS is ignored.
See z/OS DFSMSdfp Diagnosis for more information.
|
DSORG |
X |
X |
X |
X |
X |
X |
X |
X |
DSORG=organization
Specifies the organization of the data set and indicates whether
the data set contains any location-dependent information that would
make the data set unmovable.
Note: Do not code the DSORG subparameter
with DD parameters DDNAME, QNAME, RECORG. Organization | Access Method
___________________________________ _ _____________________
PS Physical sequential data set | BSAM,EXCP,QSAM,
PSU Physical sequential data set | BSAM,QSAM,EXCP
that contains |
location-dependent information |
DA Direct access data set | BDAM,EXCP
DAU Direct access data set that | BDAM,EXCP
contains location-dependent |
information |
PO Partitioned data set |BPAM,EXCP
(PDS or PDSE) |
POU Partitioned data set (PDS) that| BPAM,EXCP
contains location-dependent |
information |
CX Communications line group | BTAM
GS Graphic data control block | GAM
|
EROPT |
|
|
|
X |
|
|
X |
|
EROPT=x
- BTAM:
- Requests the BTAM on-line terminal test option. x=T
- QSAM:
- Specifies the option to be executed if an error occurs in reading
or writing a record.
- x=ACC
- System is to accept the block causing the error.
- x=SKP
- System is to skip the block causing the error.
- x=ABE
- System is to cause abnormal end of task.
- Default
- ABE
Note: Do not code the EROPT subparameter with
DD parameters DDNAME, QNAME.
|
FUNC |
|
|
X |
|
|
|
X |
|
FUNC={I|R|P|W|D|X|T} Specifies the type of data set to be opened for a 3505 Card Reader
or 3525 Card Punch. Unpredictable results will occur if coded for
other than a 3505 or 3525. - I
- Data set is for punching and printing cards.
- R
- Data set is for reading cards.
- P
- Data set is for punching cards.
- W
- Data set is for printing.
- D
- Protected data set is for punching.
- X
- Data set is for both punching and printing.
- T
- Two-line print option.
The only valid combinations of these values
are: I WT RWT RPWXT PWX
R RP PW RPWD RPWX
P RPD PWXT RWX RWX
W RW RPW RWXT
Default: P, for output
data set. R, for input data set.
Note: Do not code the FUNC
subparameter with the data-set-sequence number of the DD LABEL parameter,
or DD parameters DDNAME, QNAME.
|
GNCP |
|
|
|
|
|
X |
|
|
GNCP=n Specifies the maximum number of I/O macro instructions that the program
will issue before a WAIT macro instruction.
Note: Do not code
the GNCP subparameter with DCB subparameters BFALN, BFTEK, or DD parameters
DDNAME, QNAME.
|
INTVL |
|
|
|
|
|
|
|
X |
INTVL={n|0} Specifies the interval, in seconds, between passes through an invitation
list.
Default: 0
Note: Do not code the INTVL subparameter
with DD parameters DDNAME, FCB, QNAME, UCS.
|
IPLTXID |
|
|
|
|
|
|
|
X |
IPLTXID=member Specifies the name of the partitioned data set (PDS) member that
you want loaded into a 3704/3705 Communications Controller. The DCB
IPLTXID subparameter overrides IPLTXID in the TERMINAL macro representing
the NCP.
Note: Do not code the IPLTXID subparameter with DD
parameters DDNAME, DSNAME, QNAME.
|
KEYLEN |
X |
X |
X |
|
X |
|
|
X |
KEYLEN=bytes The KEYLEN keyword subparameter is described on the DD KEYLEN parameter, section KEYLEN parameter.
|
LIMCT |
X |
|
|
|
|
|
|
|
LIMCT={blocks|tracks} Specifies how many blocks (if relative block addressing is used)
or how many tracks (if relative track addressing is used) are to be
searched for a free block or available space. This kind of search
occurs only when DCB OPTCD=E is also specified; otherwise, LIMCT is
ignored. If the LIMCT number equals or exceeds the number of blocks
or tracks in the data set, the entire data set is searched.
Note: Do not code the LIMCT subparameter with DD parameters DDNAME,
QNAME.
|
LRECL |
|
X |
X |
|
X |
|
X |
X |
LRECL=bytes The LRECL keyword subparameter is described on the DD LRECL parameter, section LRECL parameter.
|
MODE |
|
|
X |
|
X |
|
X |
|
MODE= {C [O]}
{E [R]}
Specifies the mode of operation to be
used with a card reader, a card punch, or a card read-punch. - C
- Card image (column binary) mode
- E
- EBCDIC mode
- O
- Optional mark read mode
- R
- Read column eliminate mode
If you specify R, you must also specify either
C or E. Do not code the MODE subparameter for data entered through
the input stream except in a JES3 system.
Do not code MODE=C
for JES2 or JES3 output.
Default: E
Note: Do not code
the MODE subparameter with DCB subparameters KEYLEN, PRTSP, TRTCH,
or DD parameters DDNAME, KEYLEN, QNAME.
|
NCP |
|
X |
X |
|
|
|
|
|
NCP=n Specifies the maximum number of READ or WRITE macro instructions
that may be issued before a CHECK macro instruction is issued to test
for completion of the I/O operation. The maximum number is 255 for
BSAM and BPAM, but may actually be smaller depending on the size of
the address space. If chained scheduling is used, the number should
be greater than 1.
Default: 1
Note: Do not code
the NCP subparameter with DCB subparameter BUFMAX, or DD parameters
DDNAME, QNAME.
|
NTM |
|
|
|
|
|
|
|
|
NTM=tracks Specifies the number of tracks to be used for a cylinder index.
When the specified number of tracks has been filled, a master index
is created. The DCB NTM is needed only when the DCB OPTCB=M. If
you specify OPTCD=M but omit NTM, the master index option is ignored.
Note: Do not code the NTM subparameter with DCB subparameter
PCI, or DD parameters DDNAME, QNAME.
|
OPTCD |
X |
X |
X |
|
X |
|
X |
X |
Specifies the optional
services to be performed by the control program. All optional services
must be requested in one source, that is, in the data set label of
an existing data set, in the DCB macro, or in the DD DCB parameter.
However, the processing program can modify the DCB OPTCD field.
Code the characters in any order; when coding more than one, do not
code commas between the characters. Note: Do not code the OPTCD
subparameter with DD parameter DDNAME.
BDAM: OPTCD= {A}[E][F][W]
{R}
- A
- indicates that the actual device addresses are to be specified
in READ and WRITE macro instructions.
- R
- indicates that relative block addresses are to be specified in
READ and WRITE macro instructions.
- E
- indicates that an extended search (more than one track) is to
be performed for a block of available space. LIMCT must also be coded.
Do not code LIMCT=0 because it will cause an abnormal termination
when a READ or WRITE macro instruction is executed.
- F
- indicates that feedback can be requested in READ and WRITE macro
instructions and the device is to be identified in the same form as
it was presented to the control program.
- W
- requests a validity check for write operations on direct access
devices.
|
OPTCD (continued) |
|
|
|
|
|
|
|
|
BPAM: OPTCD=
{C|W|CW} - C
- has no effect.
- W
- requests a validity check for write operations.
BSAM and QSAM: OPTCD= {B }
{T }
{U[C] }
{C[T][B][U] }
{H[Z][B] }
{J[C][U] }
{W[C][T][B][U]}
{Z[C][T][B][U]}
{Q[C][T][B] }
{Z }
- B
- requests that the end-of-volume (EOV) routine disregard the end-of-file
(EOF) recognition for magnetic tape. For an input data set on a standard-labeled
(SL or AL) tape, the EOV routine treats EOF labels as EOV labels until
the volume serial list is exhausted. This option allows SL or AL tapes
to be read out of volume sequence or to be concatenated to another
tape with the same data set name using one DD statement. See "Data
Sets that Span Libraries" in z/OS MVS JCL User's Guide for a description of allocation processing for multi-volume
data sets created in different tape libraries.
- C
- requests chained scheduling.
- H
- requests hopper empty exit for optical readers or bypass of DOS
checkpoint records.
- J
- for a data set to be printed on an AFP printer, instructs the system that the logical record for each output data
line contains a table reference character (TRC). The TRC identifies
which character arrangement table in the CHARS parameter is to be
used to print the line. Before specifying OPTCD=J, see PSF for z/OS: User's Guide.
|
OPTCD (continued) |
|
|
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|
|
|
|
|
BSAM and QSAM (continued):- Q
- indicates that all the user data in the data set is in ASCII.
BSAM or QSAM converts the records from ASCII to EBCDIC when reading
and converts the records from EBCDIC to ASCII when writing. The data
set must reside on magnetic tape and must not contain IBM® standard
labels. The record format (RECFM) must not be V but can be D. If
the label type is ISO/ANSI/FIPS, specified as LABEL=(,AL), the system
forces OPTCD=Q.
- T
- requests user totaling facility. T cannot be specified for a
SYSIN or sysout data set.
- U
- for 1403 or 3211 Printers with the Universal Character Set (UCS)
feature and for the 3800, permits data checks and allows analysis
by an appropriate error analysis routine. If U is omitted, data checks
are not recognized as errors.
- W
- requests a validity check for write operations on direct access
devices. Requests "tape write immediate" mode on a cartridge tape
device such as the IBM 3490 Magnetic Tape Subsystem.
- Z
- for magnetic tape reel input, requests that the control program
shorten its normal error recovery procedure. When specified, a data
check is considered permanent after five unsuccessful attempts to
read a record.
OPTCD=Z is ignored if chained scheduling or a tape
cartridge is used. For a PDSE, all options except OPTCD=J are ignored.
EXCP: OPTCD=Z - Z
- for magnetic tape reel input, requests that the control program
shorten its normal error recovery procedure. When specified, a data
check is considered permanent after five unsuccessful attempts to
read a record. OPTCD=Z has no effect on a tape cartridge.
|
PCI |
|
|
|
|
|
|
|
X |
{([N][,N])}
PCI= {([R][,R])}
{([A][,A])}
{([X][,X])}
Specifies (1) whether or not a program-controlled
interruption (PCI) is to be used to control the allocation and freeing
of buffers and (2) how these operations are to be performed. The first
operand applies to receiving operations and the second to sending
operations. - N
- specifies that no PCIs are taken while filling buffers during
receiving operations or emptying buffers during sending operations.
- R
- specifies that after the first buffer is filled or emptied, a
PCI occurs during the filling or emptying of each succeeding buffer.
The completed buffer is freed, but no new buffer is allocated to
take its place.
- A
- specifies that after the first buffer is filled or emptied, a
PCI occurs during the filling or emptying of the next buffer. The
first buffer is freed, and a buffer is allocated to take its place.
- X
- specifies that after a buffer is filled or emptied, a PCI occurs
during the filling or emptying of the next buffer. The first buffer
is not freed, but a new buffer is allocated.
You can omit the parentheses if you code only
the first operand.
Default: (A,A)
Note: Do not code
the PCI subparameter with DCB subparameter NTM, or DD parameters
DDNAME, QNAME.
|
PRTSP |
|
|
X |
|
X |
|
X |
|
PRTSP={0|1|2|3} Specifies the line spacing for an online printer. PRTSP is valid
only for an online printer and only if the RECFM is not A or M. PRTSP=2
is ignored if specified with the DD SYSOUT parameter. 0 - spacing
is suppressed, 1 - single, 2 - double, 3 - triple spacing
JES2 ignores PRTSP for sysout data sets.
Default: 1
Note: Do not code the PRTSP subparameter with DCB subparameters KEYLEN,
MODE, STACK, TRTCH, or DD parameters DDNAME, KEYLEN, QNAME.
|
RECFM |
X |
X |
X |
|
X |
|
X |
X |
RECFM=format The
RECFM keyword subparameter is described on the DD RECFM parameter, section RECFM parameter.
|
RESERVE |
|
|
|
|
|
|
|
X |
RESERVE=(bytes1,bytes2) Specifies the number of bytes (0 through 255) to be reserved in a
buffer for insertion of data by the DATETIME and SEQUENCE macros. - bytes1
- indicates the number of bytes to be reserved in the first buffer
that receives an incoming message.
- bytes2
- indicates the number of bytes to be reserved in all the buffers
following the first buffer in a multiple-buffer header situation.
Default: (0,0)
Note: Do not code the
RESERVE subparameter with DCB subparameters CYLOFL, RKP, or DD parameters
DDNAME, KEYOFF, QNAME, UCS.
|
RKP |
|
|
|
|
X |
|
|
|
RKP=number With
SMS, use the DD KEYOFF or DATACLAS parameter. Specifies the position
of the first byte of the record key in each logical record. The first
byte of a logical record is position 0.
If RKP=0 is specified
for blocked fixed-length records, the key begins in the first byte
of each record. OPTCD=L must not be specified.
If RKP=0 is
specified for unblocked fixed-length records, the key is not written
in the data field. OPTCD=L can be specified.
For variable-length
records, the relative key position must be 4 or greater, if OPTCD=L
is not specified; the relative key position must be 5 or greater,
if OPTCD=L is specified.
For EXCP processing, RKP can be coded
but is ignored.
Default: 0
Note: Do not code the RKP
subparameter with DCB subparameter RESERVE, or DD parameters DDNAME,
FCB, KEYOFF, UCS.
|
STACK |
|
|
X |
|
X |
|
X |
|
STACK={1|2} Specifies
which stacker bin is to receive a card.
Default: 1
Note: Do not code the STACK subparameter with DCB subparameters KEYLEN,
PRTSP, TRTCH, or DD parameters DDNAME, KEYLEN, QNAME.
|
THRESH |
|
|
|
|
|
|
|
X |
THRESH=nn Specifies
the percentage of the nonreusable disk message queue records that
are to be used before a flush closedown occurs.
Default: Closedown
occurs when 95 percent of the records have been used.
Note: Do not code the THRESH subparameter with DCB subparameter CPRI, or
DD parameters DDNAME, OUTLIM, QNAME.
|
TRTCH |
|
|
X |
|
X |
|
X |
|
TRTCH={C|E|T|ET}
{COMP|NOCOMP} With C, E, T, or ET: specifies the recording technique
for 7-track tape. - C
- specifies data conversion, odd parity, and no translation.
- E
- specifies no data conversion, even parity, and no translation.
- T
- specifies no data conversion, odd parity, and that BCD to EBCDIC
translation is required when reading and EBCDIC to BCD translation
when writing.
- ET
- specifies no data conversion, even parity, and that BCD to EBCDIC
translation is required when reading and EBCDIC to BCD translation
when writing.
Default: no conversion, odd parity, and no
translation.
With COMP or NOCOMP: specifies data compaction
or no data compaction on a tape device enabled for compaction. Data
compaction is not supported with ISO/ANSI labels. - COMP
- specifies data compaction.
- NOCOMP
- specifies no data compaction
Defaults: On an IBM standard
label tape, data sets after the first data set have the same compaction
value (COMP or NOCOMP) as the first data set. The system ignores
any compaction specified on data sets after the first. The system
takes the compaction value from the first source that specifies it.
The following sources can specify compaction: - TRTCH subparameter.
- Data class, as set by the storage administrator. The tape, however,
does not have to be system-managed.
- DEVSUPxx member of SYS1.PARMLIB.
- The hardware model. For the IBM 3480,
the default is NOCOMP. For the IBM 3490,
the default is COMP.
See z/OS MVS JCL User's Guide for information about using IEFBR14 and the TRTCH subparameter.
Note: Do not code the TRTCH subparameter with DCB subparameters
KEYLEN, MODE, PRTSP, STACK, or DD parameters DDNAME, KEYLEN, QNAME.
Note: TRTCH is not applicable for DASD data sets. If specified,
it will be ignored.
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