I have a flowgraph with a simple FDMA implementation with two channels. One channel has a constant stream. The other channel has complex sample bursts generated in a custom python function, which I package as a PDU. I apply the frequency modulation within
the python file to place it in the correct frequency channel. I send the PDU to an eventstream source and then add the two channels in an add block before sending the merged signal to a USRP sink. I am seeing latencies of over a second from the PDU generation
to when the eventstream source sends them on. My sample rate is ~5 Ms/s and my PDU is about 1.25 MS, so about a quarter of a second. My eventstream source block is using ASAP event placement and MEMCPY settings.
Is this level of latency expected? I do not fully understand the merge behavior of the eventstream source, but I would expect perhaps 2X the PDU size of latency if it has a PDU length number of zeros in it's buffer before inserting the PDU.