DATA HANDLING SYSTEM ERROR AND FAULT DETECTING AND DISCRIMINATING MAINTENANCE ARRANGEMENT

摘要

A maintenance arrangement responds to a false signal condition, produced by a data handling system, by recycling the timing generator controlling the data handling system to cause the signals in question to be repeated. In order to determine whether the false signal condition occurred only momentarily or remains present during the recycle operation, two types of detecting circuits are provided. Error detecting circuits respond if the false signal condition has a single occurrence, and does not remain present during the recycle operation and thus is interpreted as an error condition caused by the spurious introduction of noise pulses or the like, and fault detecting circuits respond if the false signal condition continues to be present or reappearing during the recycle operation to indicate a fault condition and to request other equipment to service the data handling system. Also, the maintenance arrangement designates the group of signals resulting in the false signal condition by storing group-identifying information in the memory of the data handling system so that the servicing equipment can determine the source of the problem. A register of the data handling system storing information relating to the group of signals resulting in the false condition is inhibited from being altered by the maintenance arrangement, which sets a freeze indicator in such a register so that all other information stored therein is preserved for use by the servicing equipment.