LabVIEW Idea Exchange
So one can set many of the standard properties for VISA connections. However the serial port latency setting is not one of these. It can easily be set by a standard POSIX ioctl call for both linux and MacOS (who the heck knows how Windows does it). Many character based devices can be manipulated through these ioctl calls.
To be specific, the FTDI USB-Serial port driver chips used in MANY devices as a USB interface or just as a serial port have a slow default latency that is fine for preserving CPU cycles but not great for modern high speed custom communication.
1. Just add a a property that sets the serial port latency using an ioctl IOSSDATALAT property configuration.
2. More generally allow an interface that will call ioctl with a supplied property and the LV programmer can pass the correct property configuration.
3. Less satisfying but possibly easier to implement is to have the VISA property be the file descriptor number. This simplifies the programming where one has to now get the "Name" property and then search the process information table for that "Name" (or really path) and then extract the file descriptor. Only then can one set the latency for that device.
