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Entry  22 Feb 2016, ZiyiGuo, Forum, Problem with BLTRead 
    Reply  23 Feb 2016, Pierre-Andre Amaudruz, Forum, Problem with BLTRead 
       Reply  02 Mar 2016, ZiyiGuo, Forum, Problem with BLTRead 
Message ID: 1167     Entry time: 02 Mar 2016     In reply to: 1165
Author: ZiyiGuo 
Topic: Forum 
Subject: Problem with BLTRead 
> > Dear all,
> >
> > I'm using MIDAS system and CAEN V1721 to digitize the waveform from photomultipliers (
> > and the link bridge to PC is V2718 ). I use BLTRead to read data of the digitizer, but
> > I found that if the event counting rate is high ( about 100KB/s ), the communication
> > of V1721 and PC would be suspended randomly, and I get an error code of -2. Could you
> > give me some suggestion? Thanks a lot.
> Hi,
> Can you provide the BLTread call fragment code and the PC /var/log/messages at the time of
> the hang up.
> What is needed to restart the daq?

Hi Pierre-Andre,

Sorry for my late reply, because the data acquisition system now is running other experiment.
Here is my code. Is there something wrong? Thanks!

/* Read FADC data */
int NByteOfOneEvent = HeadSize + SampSize * NChannel;
int NDWordOfOneEvent = NByteOfOneEvent/4;

/* 1. Create FADC bank. One bank for one branch of a tree or one array branch with length. */
bk_create(pevent, "FADC", TID_DWORD, (void**)&pdata);

uint32_t size_remaining_dwords;
int dwords_read;

/* 2. Read out the event and assign them to pdata (bank buffer) */
//read size of event to be read
sCAEN = CAENComm_Read32(hFADC[card], V1721_EVENT_SIZE, &size_remaining_dwords);

if( size_remaining_dwords < NDWordOfOneEvent ) {
printf("\r\nSize of available data is less than the required size of one event.\r\n");

/* Read */
DWORD *pFadcData;
sCAEN = CAENComm_BLTRead(hFADC[card], V1721_EVENT_READOUT_BUFFER, pdata, NDWordOfOneEvent, &dwords_read);

// These code in "if" is for restart communication and save the time information if the communication was suspended

if(sCAEN != 0)
//printf("sCAEN =%d \n", sCAEN);
time_t t = time(0);
char tmp[64];
strftime(tmp,sizeof(tmp),"%Y/%m/%d %X %Z",localtime(&t));
fprintf(logfile,"\n Here met communication error \n");
printf(" Here met communication error \n");

//re-establish communication
sCAEN = CAENComm_CloseDevice(hFADC[card]);
fprintf(logfile,"sCAEN =%d, device closed **********\n", sCAEN);


sCAEN = CAENComm_OpenDevice(CAENComm_PCIE_OpticalLink, l, d, FADCBA[card], &(hFADC[card]));

if (sCAEN == CAENComm_Success) {
fprintf(logfile,"re-establish communication, handle:%d, sCAEN=%d \n", hFADC[card], sCAEN);
else {
sCAEN = CAENComm_OpenDevice(CAENComm_PCIE_OpticalLink, l, d, FADCBA[card], &(hFADC[card]));
fprintf(logfile,"try open device again sCAEN= %d\n", sCAEN); }

//pause ongoing reading process
sCAEN = ov1721_AcqCtl(hFADC[card], V1721_RUN_STOP);
sCAEN = CAENComm_Read32(hFADC[card], V1721_EVENT_STORED, &eStored);

//discard FADC buffer
sCAEN = CAENComm_Write32(hFADC[card], V1721_SW_CLEAR, 0);
fprintf(logfile," number of %d events discarded \n\n", eStored);
sCAEN = ov1721_AcqCtl(hFADC[card], V1721_RUN_START);

//dwords_read: Number of the words that actually read from the device.
if( dwords_read != NDWordOfOneEvent ) {
printf("\r\nSize of data read out doesn't equal to the required size of one event. \r\n");

EvtCounterFadc[card] = *(pdata+2) & 0x00ffffff;

/* 3. Update bank pointer position */
pdata += dwords_read;

/* 4. Finish one bank */
bk_close(pevent, pdata);
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