Chapter 7 559
Command Definitions S-SO
SETJCW
SETJCW PROGCNTR 0
....
SETVAR PROGCNTR 65536
JCW VARIABLE RECLASSIFIED AS A STANDARD VARIABLE
(CIWARN 8126)
PROGCNTR is now a user-defined variable and does not function as a job control word.
JCWs can be tested against specific values. The user can use IF and WHILE conditional
statements that act according to the results of these tests. The user-defined JCWs can also
be set to user-selected values by a process so that they reflect the completion of steps
within that process. System-defined JCWs can be used to determine whether certain
events have occurred within MPE/iX.
The values in the system-reserved JCWs can be inspected by the user, but not altered.
To display the contents of a JCW use the SHOWJCW or the SHOWVAR command.
JCW Values and Mnemonics
JCWs may be assigned any positive integer value between 0 and 65,535 inclusive (%0 and
%177777). These values are treated as 16-bit unsigned integers by MPE/iX, since all 16
bits are used for numeric information, rather than using the most significant bit as a sign
bit.
MPE/iX treats the two most significant bits of a JCW in a special way: the bits define
"bases" or "steps" of 16K each. Each of these steps is given a mnemonic to simplify
references to it or to the numbers between steps. If the 14 least significant bits are
considered to be zeros, the two "step" bits, step value (in decimal), and mnemonic have the
following relationship:
It is important to remember that these mnemonics are not the names of JCWs. They
cannot be used as user-defined JCW names.
You may use a combination of mnemonics and numbers to indicate numeric values
between steps. If you specify a mnemonic and a number with no intervening spaces, an
implied addition takes place. For example, WARN3 has a value of 16,387, since it is WARN
(16,384) plus 3. The value of the mnemonic plus the appended number value may not
exceed 65,535. Again, no valid value of the form, mnemonic[number], may be used as a
valid user-defined jcwname. An explicit addition or subtraction can also be specified, using a
+ or - sign, as in OK+7 (7) or WARN-4 (16,380). A mnemonic may also be added to another
mnemonic, as in WARNFATAL.
Bit Value Step Value Mnemonic
00 0 OK
01 16,384 WARN
10 32,768 FATAL
11 49,152 SYSTEM
