ETO descriptors

When you are enabling ETO support in your installation, you can optionally request that IMS produce ETO descriptors during system definition. You do this with the ETOFEAT keyword in the IMSCTRL macro.

Descriptors contain information about terminal devices and users that is required to establish dynamic sessions. Four types of descriptors are:

Descriptors that are created during system definition are placed in member DFSDSCMx, which resides in the IMS.PROCLIB data set. If you perform subsequent system definitions of the same stage 1 input deck, the DFSDSCMx members are overwritten. If you use TSO or a z/OS® utility to create descriptors, you can place the descriptors in member DFSDSCTx to avoid loss when member DFSDSCMx is replaced. You can also use TSO or an z/OS utility to update descriptors in DFSDSCMx that were created during system definition.

The suffix for DFSDSCMx is always the nucleus suffix. The default suffix for DFSDSCTy defaults to 0; however, you can specify it with the DSCT= JCL parameter. Each descriptor statement must be 80 characters in length. All statements are translated to uppercase.