Response to timeout in the case of direct I/O access
The following operations can result in timeout: L PB; LPW; T PB; T PW; LIR; TIR; TNB.
The timeout (QVZ) error occurs if a module fails to acknowledge within 160 µs of being
accessed. The cause may be a program error, a defect in the module or the removal of
the module during the RUN mode. The operating system stores the absolute module
address at which the QVZ occurred in system data word 103 (EACEH) and calls OB23. If
OB23 does not exist, the CPU goes to STOP with QVZ.