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Triggering the History Buffers

The history PVs have two states: `armed' or `idle'. In `armed' state the history waits for a triggering event and upon reception, starts writing data into the buffers. Once in `armed' state, the history is `busy' and cannot be accessed. Most notably: at the moment it cannot be disarmed.

After filling up, an `armed' buffer returns to `idle' state and can be read and rearmed.

A history buffer is armed by setting its RARM field (The respective PVs are 116-BPM:history.RARM, 132-BPM:history.RARM) to a non-zero value:


Till Straumann 2005-06-02