User manual

Windows Server Program
ComTec GmbH 5-2
Two parameters allow to define the DMA transfer settings. 'timeout' defines the time after a DMA
transfer is terminated if it is not finished, and 'blocksize' defines the number of double words of
data to be transmitted in a single DMA transfer. The default value of 1024 is for moderate
counting rates. For very high counting rates you may chose a value like 4096 or 16384. One
special thread in the software handles only the DMA transfer. It starts immediately after a transfer
is completed a new one acting on a second buffer and signals to a second thread that a buffer is
ready for evaluation. These two threads run in parallel to the message handling and display
refresh routines. Windows NT is able to perform the threads automatically in parallel on two
processors on a dual processor system. Another parameters that can be set only by editing the
MPA3.INI file is the updaterate in msec for the refresh of the status. Very important is also the
correct setting of the ADC handshake polarities. If you have for example Silena ADCs, remove
the semicolon at the first position of the line after “; Silena or Lane ADC’s” and insert a semicolon
in the line after “; FAST or Canberra ADC’s”.
5.1.2. Action menu
The server program normally is shown as an icon in the taskbar. After clicking the icon it is
opened to show the status window. Using the „Start“ menu item from the action menu a
measurement can be started. In the status window every second the acquired events, the
counting rate and the time are shown. Clicking the „Halt“ menu item the measurement is stopped
and via „Continue“ proceeded.
Figure 5.2: Sample MPA3.INI file