In Port Select Mode B (printer selection at beginning of printing), a print job is ended only when no characters are received by the Model 24SII DES from the computer for the specified Input Inactivity Timeout period only.
CAUTION: The Input Inactivity Timeout should not be set to 0 (zero) seconds (disabled) in Port Select Mode B. Mode B operation cannot recognize a manual disconnect or clear buffer command until the current print job is ended via the inactivity timeout period.
If the buffer of the Model 24SII DES is filled to capacity, the unit will drop the DTR line or send an XOFF to the computer, causing the computer to stop sending characters until the buffer can accept more data. In this case, the time that the computer is not sending characters is not counted as part of the Input Inactivity Timeout.
When a user makes a request to print, the data is sent to the Model 24SII DES and stored in the spooling buffer (standard 1MB, optional up to 16MB). All users may simultaneously input data to this dynamically allocated buffer. Therefore, the entire buffer could be occupied by data from one user, if only one is active, or the buffer could be simultaneously distributed to all users, maximizing buffer utilization.
Print jobs are buffered and put into a queue in the same order in which they were sent to the Model 24SII DES. These print jobs are then sent to the printer in the same order in which they were queued.
When a computer port LED illuminates, this indicates a connection between the computer on that port and the buffer of the Model 24SII DES. When a printer port LED illuminates, this indicates the buffer of the Model 24SII DES has connected to the printer on that port.