The command recognition stage analyzes the data received from the input unit. It proceeds in the order in which it receives the data. Only a DCL is serviced with priority, e.g. a GET (Group Execute Trigger), e.g., is only executed after the commands received before. Each recognized command is immediately transferred to the data set but not executed immediately.
The command recognition detects syntax errors in the commands and transfers them to the status reporting system. The rest of a command line after a syntax error is ignored.
If the command recognition detects a delimiter or a DCL, it also requests the data set to perform the necessary instrument hardware settings. Subsequently it is immediately prepared to process further commands. This means that new commands can already be serviced while the hardware is still being set ("overlapping execution").