This section details the specifics to running SI_SCOPE with the operating system supplied driver. This option allows you to use hardware for serial analysis that SIDRVR may not recognize such as USB-RS232 converters. Converters such as these come with a custom driver that allow Win32 applications to access the hardware through the standard Windows communications API.
Before using this option you need to be aware of the
limitations imposed by this configuration. SI_SCOPE will
normally use its own driver (SIDRVR) as detailed in the previous chapters.
SIDRVR is a 32-bit driver designed for serial analysis. It uses a buffering
mechanism that will preserve the sequence of events that occur on the serial
line being analyzed and will time stamp received events at the interrupt level.
The operating system driver will hold the data received from each port in separate buffers. Therefore it is possible that SI_SCOPE will display events out of sequence on the screen when using this driver. This can occur when the data from one device on the line being analyzed is responded to from the second device faster than the time it takes the operating system to notify SI_SCOPE of the first event. When SI_SCOPE is notified of the first event both buffers have data in them and sequencing can be lost. Even if this occurs the only thing effected is the order of the events, the source of the events (DTE or DCE) will be correctly displayed. Secondly the time stamps recorded when using the Windows API represent the time SI_SCOPE received the event from the API not the time the event actually occurred.
To configure SI_SCOPE to use the Windows driver click on the settings menu from within SCOPECFG and choose the option "Configure Board Type". From the drop down list choose the Windows API/USB option. Next select the ports you want to use by clicking on the Settings menu and choosing the "Configure Port Parameters" option. Select the values to use for each port from the drop down menus.
If you had previously configured
SI_SCOPE to use SIDRVR you should restart your system. If
SIDRVR's hardware pre-allocation option was enabled it will automatically be
disabled by SCOPECFG when using the Windows driver. If you switch back to using
SIDRVR you will need to turn that option back on.