Requesting Different Levels of ERP Processing

You can request the system to limit error recovery procedure (ERP) processing to selected functions, typically when EXCP or EXCPVR processing has encountered an I/O error. The processing selections available depend upon the device type.

For all devices, except magnetic tape subsystems that use cartridges, the following processing levels are available:

No ERP processing. ERP processing does not attempt error recovery or issue messages. However, ERP processing can perform recovery for non-error unit checks for logging, forced logging mode and buffered log overflow. To request no ERP processing, set at least one of the DCBIFIOE bits on in the DCBIFLGS field in the DCB.
Full ERP processing. ERP processing performs such functions as logging the errors, logging data collected by a control unit for a device, retrying errors, issuing error messages and processing requests from the device. You do not have to request full ERP processing; it is the system default.

For magnetic tape subsystems that use cartridges, such as the 3490 or 3590-1, the following processing levels are available:

Basic ERP processing. ERP processing logs the errors, logs data collected by a control unit for a device and processes requests from a device. In this case, the system does not issue messages or retry errors. To request basic ERP processing, set one of the DCBIFIOE bits on in the DCBIFLGS field in the DCB.
Intermediate ERP processing. ERP processing performs the functions provided by basic processing and also issues any permanent error messages. To request intermediate ERP processing, define an IOBE and set IOBEPMSG on in IOBEERPM. In addition, set at least one of the DCBIFIOE bits on in the DCBIFLGS field in the DCB.
Full ERP processing. ERP processing performs such functions as logging the errors, logging data collected by a control unit for a device, retrying errors, issuing error messages and processing requests from the device. You do not have to request full ERP processing; it is the system default. Bits in DCBIFIOE must be 0. The DCB macro assembles them as zeros.