| 摘要 |
A device (2) for testing a computer (4) is operable to determine the times at which the computer system is unavailable by repeatedly and automatically sending messages to the computer (4), and determining whether a response is received within a predetermined interval. The device (2) preferably decides that the computer system is available in response to an acknowledgement that the device has successfully logged onto the computer. The device (2) then preferably repeatedly sends transaction messages to which a program in the computer (4) responds. If the device (2) fails to receive responses to a predetermined number of transaction messages within a predetermined interval, the device (2) decides that the computer system has become unavailable. The device (2) provides a printed record indicating the times at which the computer system became available and unavailable, and generates an immediate alarm whenever the computer system becomes unavailable or a response to a transaction message is not received within a predetermined interval. <IMAGE> |
