The time required for the processor to scan all I/O modules, writing output data and reading input data. For local I/O, the I/O scan is typically in sequence with the program scan, in one overall scanning sequence. For remote I/O, the I/O scan is separate from the program scan; it is either left asynchronous to the program scan or is synchronized to the program scan by buffering input data from the I/O scan to write it into the input image table only immediately before the start of each program scan.