Message buffer format

Figure 1 shows the format of the message area.

Figure 1. Message Buffer Format

The message buffer format is described in the text that follows.

The address of the message area is returned in register 1. The area comes in two parts. Each part is a separate variable length record. If the data set being analyzed is not a PDSE, an extended format data set, or a UNIX file, only the first area is created. Otherwise, both areas are created. The first area is 120 characters long, and begins with a field of blanks; you can use the blank field to add your own remarks to the message. The text of the second area begins 8 bytes past the end of the first message. It is 128 characters long and ends with several blanks (reserved for later definition by IBM®).

Fields contain EBCDIC characters unless otherwise stated here. For most character fields if the system cannot get the information, the field contains asterisks.

If you suspect a system software error, report the SMS return code, reason code and diagnostic code and UNIX diagnostic information to your IBM service representative.

Table 1. Message Area Details
Offset	Length	Description
0	2	Length of variable-length block in binary. Always 128.
2	2	X'0000'.
4	2	Length of variable-length record in binary. Always 124.
6	2	X'0000'.
Input, not using LBI and access method is not BISAM or QISAM
8	4	Data address (binary). Might be zero.
12 (C)	2	Number of bytes read (binary). Might be zero.
14 (E)	35	Blanks.
Input, using LBI
8	4	Binary zeroes.
12 (C)	4	Data address (binary).
16 (10)	4	Binary zeroes.
20 (14)	4	Number of bytes read (binary).
24 (18)	25	Blanks.
Output or access method is BISAM or QISAM
8 (8)	41	Blanks. If BISAM or QISAM, this might contain a VSAM message as described in Reason code (physical errors).
All
49 (31)	1	Comma.
50 (32)	8	Job name.
58 (3A)	1	Comma.
59 (3B)	8	Step name.
67 (43)	1	Comma.
68 (44)	4	Device number in hexadecimal or one of the following values: JES (spooled data set or a subsystem data set (SUBSYS=)), OMVS (UNIX file or directory) or N/A (BISAM or QISAM).
72 (48)	1	Comma.
73 (49)	1	Device class: D (direct access), T (tape), U (unit record) or * (other). For BISAM or QISAM, the previous byte and this byte contain this value: DA.
74 (4A)	1	Comma.
75 (4B)	8	DD name.
83 (53)	1	Comma.
84 (54)	6	Operation attempted such as READ, WRITE, GET, PUT, POINT or ENDREQ.
90 (5A)	1	Comma.
91 (5B)	15	Error description. Might be N/A or NOT APPLICABLE. See SYNADAF error descriptions. If it indicates a padding error, then the data set is extended format and the data was damaged when it was written. This might be due to hardware error, an operator cancel or time out while the control unit was transferring data.
106 (6A)	1	Comma.
Direct access
107 (6B)	14	Actual track address and block number (BBCCHHR). If compressed format data set, this is a relative block number (RBN) in bytes 107-113. If a logical error in a compressed format data set and not a physical error, this may contain asterisks. If the error was in POINT or backspace, this can be TTR UNKNOWN. If BDAM and the error was an invalid request, character zeroes. If UNIX file, low order portion of file offset in hex.
121 (79)	1	Comma.
122 (7A)	5	Access method.
127 (7F)	1	Message code. If S, then a second message exists beginning at offset 136.
Magnetic tape
107 (6B)	10	Relative block number in data set (decimal).
117 (75)	1	Comma.
118 (76)	5	Access method.
123 (7B)	5	Blanks.
Not direct access or magnetic tape
107 (6B)	14	Asterisks.
121 (79)	1	Comma.
122 (7A)	6	Access method.
All device classes
128 (80)	4	Parameter register 0 (PARM2) passed to SYNADAF. Binary.
132 (84)	4	Parameter register 1 (PARM1) passed to SYNADAF. Binary.
The rest of the area exists only if the byte at +127 contains S. Currently this occurs only for PDSE, extended format data set or z/OS UNIX file.
136 (88)	2	Length of variable-length block in binary. Always 128.
138 (8A)	2	X'0000'.
140 (8C)	2	Length of variable-length record in binary. Always 124.
142 (8E)	2	X'0000'.
144 (90)	1	Comma.
145 (91)	3	Concatenation number (first data set is 0).
148 (94)	1	Comma.
149 (95)	7	Member locater token (MLT, simulated TTR) in hex if PDSE or UNIX directory with BPAM. First byte is blank. Zero if extended format data set.
156 (9C)	1	Comma.
157 (9D)	10	A decimal number. Record number in PDSE member, record number in UNIX file or block number in extended format or compressed format data set. Leading zeroes are blanks. The first record or block is 1.
167 (A7)	1	Comma.
168 (A8)	8	One of the following hex codes: SMS return code for a PDSE. Refer to z/OS DFSMSdfp Diagnosis. Media manager return code for an extended format data set. Refer to z/OS DFSMSdfp Diagnosis. Feedback code for a UNIX file. The feedback code is similar to what is described for RPLFDBWD for VSAM in Record management return and reason codes. The third and fourth digits (return code) are one of these values like RPLRTNCD: 08 Logical error 0C Physical error. For a UNIX file the seventh and eighth digits are described in Table 2.
176 (B0)	1	Comma.
177 (B1)	8	SMS reason code in hex unless a UNIX file with a physical I/O error. In that case, the name of the failing UNIX service.
185 (B9)	1	Comma.
186 (BA)	2	SMS diagnostic code. Contains “**” if not available. Otherwise refer to Table 4.
188 (BC)	1	Comma if UNIX file. Blank otherwise.
189 (BD)	16	UNIX diagnostic information if UNIX file and a physical I/O error, otherwise blanks. Format is xxxx-yyyyyyyy, which are the z/OS UNIX return and reason codes in hex.
205 (CD)	59	Blanks.

The two digits in the feedback code at offset 174 and 175 for a UNIX file are hexadecimal values like RPLERRCD. Refer to Table 2 and Table 3.

Table 2. Feedback Code at Offset 174 and 175 for a Logical Error
Offset	Description
04 (4)	End of data.
10 (16)	Beyond end of file or invalid record.
1C (28)	System is not able to extend the file.
20 (32)	Invalid position in file.
28 (40)	Insufficient virtual storage.
2C (44)	Buffer too small.
30 (48)	Invalid option in internal system control block.
44 (68)	Invalid internal system control block.
48 (72)	Invalid option in internal system control block.
54 (84)	Invalid option in internal system control block.
68 (104)	Invalid option in internal system control block.
DA (218)	Unrecognized internal system return code.

Table 3. Feedback Code at Offset 174 and 175 for a Physical Error
Offset	Description
04 (4)	Read error.
10 (16)	Write error.
DA (218)	Unrecognized internal system return code or option.

Table 4. Hexadecimal Codes in the SMS Diagnostics Code Field at Offset 186
Code (hex)	Description
01	System logic error in asynchronous routine.
02	System logic error (program check).
03	System logic error. Bad SMS return code.
04	Invalid locater token passed to POINT. User error.
05	POINT issued when no member was connected. User error.
06	The DCB was open for output and POINT was called with an MLT for other than the current member. User error.
07	POINT issued when I/O was outstanding. User error.
08	POINT issued with an RLT that is too big for the file or member. User error.
09	Connect or reconnect unable to get file lock for POINT. Might be a user error.
0A	POINT issued with invalid MLT. User error.
0B	Padding error for extended format data set.
0C	I/O error for extended format data set.
0D	I/O error for a compressed format data set.
0E	Data set is compressed format and READ or WRITE request was for an RBN that exceeds the X'FFFFFF' limit and BLOCKTOKENSIZE=LARGE was not coded.