Number of Characters Queued

Binary integer with the number of received characters in the device driver receive queue. This is a memory buffer between the memory pointed to by the READ request packet and the receive hardware for this COM device. The application cannot assume that there are no unsatisfied Read requests if there are characters in the device driver receive queue.

Note: The behavior of data movement between the Read request and the receive queue can change with each release of the physical device driver. Applications should not have a dependency on this information.