Experimental Physics and
Industrial Control System

     I am facing problem in I/O Interrupt for waveform record in the asyn.  If the value of waveform record change very fast then some of the samples missing or same sample repeat twice even if  before p_interruptInt32Array->callback () function the value is scanned properly by driver. But i think the read value is pushed to the callback but it is not handle that much fast in the callback.

I checked the code for interruptCallbackInput   in devAsynXXXArray.h. 

In devAsynXXXArray.c  dbScanUnlock has been used before  scanIoRequest().   Can it create problem for repeating same value?  

My assumption is as dbScanUnlock  and before scanIoRequest() execute, value change and second time triggers interrupt. This result same value for both interrupts.

I checked interrupt callback code  in devAsynInt32.c where  epicsMutexUnlock has been used after scanIoRequest(). 

Thank you

Vishnu