JCL Basics What is JCL? Job Entry Subsystem Job Processing JCL Statements JCL Parameters JOB Statement Job Statement Parameters for Job Positional Parameters ACCT NAME Keyword Parameters MSGLEVEL MSGCLASS TYPRUN PRTY CLASS RESTART REGION TIME NOTIFY EXEC Statement EXEC Statement Positional Parameters PGM PROC Keyword Parameters COND PARM ADDRSPC DD statement DD statement DD Parameters SPACE SYSIN VOL DCB SYSOUT DSN UNIT DISP |
UNIT parameter • UNIT parameter specifies an input or output device that is to be accessed. • The devices are identified by – hardware address – device type – group name or – requesting unit used by another data set in the same step. • Examples: //UNIT=S0C4 //UNIT=3390 //UNIT=SYSDA • The general syntax is: 1. UNIT=device address - It requests specific I/O unit by giving the 3 or 4-digit hardware address of the device. Four digit number must be precede by a slash(/), as in UNIT=/2301. - For example, //UNIT=S0C4 - Don’t use hardware addresses unless you want a specific hardware unit; the system may already have allocated the device to another job. 2. UNIT=device-type - It requests an I/O device by the IBM model number. - For example, //UNIT=3390 requests an available 3390 disk. - Generally, you shouldn’t use the type because your installation will replace old types with new types from time to time. 3. UNIT=device group name - It requests one of several devices grouped by the installation. A device group name is a symbolic name which is assigned to a group of devices when the system is generated. - For example, //UNIT=SYSDA Here SYSDA is a device group name. |