Changeset 887


Ignore:
Timestamp:
Jun 7, 2012 3:40:24 PM (10 years ago)
Author:
mooney
Message:

minor edits

File:
1 edited

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  • softGlue_examples/source/gated_scaler/index.rst

    r883 r887  
    77
    88This circuit shows one way to build a four channel :index:`!gated scaler`.
     9
     10Circuit and documentation: Tim Mooney
    911
    1012Circuit
     
    6466        ``0`` to ``$(P)$(H)busy1``.
    6567
     68        .. note::       A better way to abort would be to write ``0`` to the input of
     69                                ``BUF-1``. This is better because it results in the counters
     70                                being read before the busy record is cleared.
     71
    66725)      Read the accumulated counts from ``UpCntr-<n>_COUNTS``, where ``<n>`` is in
    6773        [1-4].
     
    8288-------------------
    8389
    84 Execution begins when the user writes ``1`` to ``$(P)$(H)busy1``.  This record declares
     90Execution begins when a client writes ``1`` to ``$(P)$(H)busy1``.  This record declares
    8591itself to be busy (for the purpose of ``ca_put_callback()``), and starts the counter
    8692circuit by writing the value ``1`` to the input of ``BUF-1``.  ``BUF-1`` fans the signal
     
    99105at ``1`` until it's time for the counters to stop counting.
    100106
    101 ``counting`` is sent to field output bit 17, which must actually be configured as
    102 an output, and which will generate an interrupt on the falling edge of
     107``counting`` is sent to field output bit 17, which must actually be configured
     108as an output, and which will generate an interrupt on the falling edge of
    103109``counting`` (when pulse counting has finished).  The interrupt configuration
    104 (which is not shown in the figure) is set so that the falling edge of ``counting``
    105 causes the record ``$(P)$(H)sseq1`` to process, which causes EPICS records for all
    106 four counters to process, reading their values so that a client can acquire
    107 them.
     110(which is not shown in the figure) is set so that the falling edge of
     111``counting`` causes the record ``$(P)$(H)sseq1`` to process, which causes EPICS
     112records for all four counters to process, reading their values so that a client
     113can acquire them, and then clears the busy record ``$(P)$(H)busy1``.  If the
     114client that started the scaler did so with a ``ca_put_callback()``, clearing the
     115busy record results in a "done" callback to that client.
    108116
    109117*       You can, of course, use any field output bit for this purpose, as long as
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