| 摘要 |
PURPOSE:To read surely information relating to the presence of a transmission request regardless of the operating state of an equipment by prolonging a reply time when no reply is obtained within a prescribed reply time to apply recheck. CONSTITUTION:A prescribed reply time T, an incremental time DELTAT, and the recheck number of times N are set in advance, a reset signal is sent to a clock circuit 5 to bring a variable (t) serving as a clock counter to 0, a start signal is sent to a GPIB control circuit 4 to clear a GBIB interface for check operation and a reply from an equipment being an object of polling is awaited. The waiting operation is applied for the reply time T and when no reply comes, a value adding the increment time DELTAT to the reply time T is used as a new reply time T and the operation is repeated again. When no reply comes in this way, the time is prolonged by DELTAT for check, then sure reply is attained. |
