Initialize

Initialize

The initialization function must prepare the hardware to be accessed and perform any one-time initialization. In our case, the Philips ADC/TDC will be set up:

/*!
   Initialize the modules.
   The crate must be held inhibited while the modules are initialized
   or else gates can make them busy at which point they'll ignore programming
   requests.

*/
void MyEventSegment::Initialize()
{
  branchinit(m_nB);		// Ensure the branch is initialized.
  inhibit(m_nB, m_nC);		// Hold the crate inhibited.
  
  InitTdc(1, 100, 50, 50); 
  InitAdc(2, 50, 25, 25);

  uninhibit(m_nB, m_nC);
}

Using helper functions (InitTdc and InitAdc) keeps the code uncluttered and easy to understand. In addition, breaking the code down into these small functions helps keep the complexity of a real experiment under control. For a larger experiment, you may even want to make a class out of the digitizers themselves. This has been done for many of the standard electroncis modules.

The implementation of InitTdc and InitAdc are shown below.

/*!

  Initialize a TDC.
  Clear the module, set the command register and set the 
  parameters from the common levels passed in.
  \param vsn - The virtual slot number to program in the tdc.
  \param pedestal - Common pedestal value for all channels.
  \param lld - Common low level discriminator value for all channels.
  \param uld - Common upper level discriminator value for all channels.
*/

void
MyEventSegment::InitTdc(int vsn, int pedestal, int lld, int uld)
{

  camctl(m_nB, m_nC, m_nTdc, 0, 9); // Clear

  camwrite16(m_nB, m_nC, m_nTdc, 0, 23, 0xffff); // clear ctl reg bits.
  camwrite16(m_nB, m_nC, m_nTdc, 0, 19, 7); // Enable pedestals & thresholds

  // Pedestals

  camwrite16(m_nB, m_nC, m_nTdc, 0, 17, 0); // Select pedestal memory
  for(int i =0; i < 15; i++) {
    camwrite16(m_nB, m_nC, m_nTdc, i, 20, pedestal);
  }

  // ULD:

  camwrite16(m_nB, m_nC, m_nTdc, 1, 17, 0); // Select lower level disc.
  for(int i = 0; i < 15; i++) {
    camwrite16(m_nB, m_nC, m_nTdc, i, 20, lld);
  }

  // LLD
  
  camwrite16(m_nB, m_nC, m_nTdc, 2, 17, 0); // Select upper level  disc.
  for(int i = 0; i < 15; i++) {
    camwrite16(m_nB, m_nC, m_nTdc, i, 20, uld);
  }
  
}

/*!
  Initialize the adc:
*/
void
MyEventSegment::InitAdc(int vsn, int pedestal, int lld, int uld)
{

  camctl(m_nB, m_nC, m_nAdc, 0, 9); // Clear

  camwrite16(m_nB, m_nC, m_nAdc, 0, 23, 0xffff); // clear ctl reg bits.
  camwrite16(m_nB, m_nC, m_nAdc, 0, 19, 7); // Enable pedestals & thresholds

  // Pedestals

  camwrite16(m_nB, m_nC, m_nAdc, 0, 17, 0); // Select pedestal memory
  for(int i =0; i < 15; i++) {
    camwrite16(m_nB, m_nC, m_nAdc, i, 20, pedestal);
  }

  // ULD:

  camwrite16(m_nB, m_nC, m_nAdc, 1, 17, 0); // Select lower level disc.
  for(int i = 0; i < 15; i++) {
    camwrite16(m_nB, m_nC, m_nAdc, i, 20, lld);
  }

  // LLD
  
  camwrite16(m_nB, m_nC, m_nAdc, 2, 17, 0); // Select upper level  disc.
  for(int i = 0; i < 15; i++) {
    camwrite16(m_nB, m_nC, m_nAdc, i, 20, uld);
  }
  
}

Initialize