Serial communications

Whether the XLR PRO is configured for USB, RS-232, RS-485/422, or IP socket mode, the XLR PRO handles the traffic as serial data, and the XLR PRO handles all serial traffic the same, regardless of the interface in use.

Serial buffers

Serial receive buffer

When serial data enters the XLR PRO, the data is stored in the serial receive buffer until it can be processed. Under certain conditions, the XLR PRO may not be able to process data in the serial receive buffer immediately. If large amounts of serial data are sent to the XLR PRO such that the serial receive buffer would overflow, then new data is discarded. If using RS-232, this can be avoided by using hardware flow control. Software flow control can be used regardless of which serial interface is used.

Serial transmit buffer

When serial RF data is received, the data is moved into the serial transmit buffer and sent out of the active serial interface of the XLR PRO. If the serial transmit buffer becomes full and system buffers are also full, then the entire RF data packet is dropped. Whenever data is received faster than it can be processed and transmitted out the serial port, there is a potential of dropping data.