Counter complete on PCIe 6321

I'm trying to send a count complete output pulse to a PFI channel when a counter reaches zero (Ex. Start at count 10 and counter down). The counter appears to be running without error, however the PFI output does not toggle. I know this can be done with an event callback, unfortunately the sotware latencey is insufficient for our application. Any ideas?

DAQmxCreateTask("", &_taskCounter);
DAQmxCreateCICountEdgesChan (_taskCounter, "/Dev1/ctr3","", DAQmx_Val_Rising, 10, DAQmx_Val_CountDown );
DAQmxSetCIFreqTerm(_taskCounter,"","/Dev1/PFI5");
DAQmxExportSignal(_taskCounter,DAQmx_Val_CounterOutputEvent,"/Dev1/PFI15");
DAQmxStartTask(_taskCounter);