I am using the embedded python block in GRC to realize some simple functions. All works fine in the GRC local set-up. However, if I connect a USRP sink to the flowgraph which includes that python block, and set the sample rate more than 20 MHz (I need 100 MHz in my case), it will keep output "UUUUUUUU....", and then GRC will stop working.
I tried the defaulted python block, where the output is simply multiplied by a factor k, the same overrun problem happened. And GRC works fine with the USRP sink if the python block is not used.
Does anyone know what could be the problem?