1. An article of manufacture comprising at least one computer usable medium having computer readable program code logic to determine an extended measurement word at a channel subsystem of an input/output (I/O) processing system using data from a control unit, the computer readable program code logic for performing a method comprising: sending a command message to the control unit; receiving a transport response information unit message at the channel subsystem in response to sending the command message to the control unit; extracting a plurality of time values from the transport response information unit message as calculated by the control unit; calculating an extended measurement word as a function of the extracted time values; and writing the calculated extended measurement word to computer readable memory in the I/O processing system.