Bruker NMR AV4 BSMS System, Руководство пользователя

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GAB/2
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On top of the GAB/2 menu there is the link to the Gradient Amplifier Control sub-page. This
page provides an overview over
• The overall state.
• The connected boards.
• Operating state (e. g. “operate“). If the GAB/2 is in state “off, protection” or “error” then the
current source is disconnected by a relay.
• Channel assignment: which board should listen to which LVDS commands.
Figure 10.7: GAB/2 Subsystem Control Page
The GAB/2 service functions provide detailed information for diagnostics and a push button
offset calibration (see also
Offset Re-Calibration in the Field [ } 90] ).
There are further links for pre-emphasis parameter setting and logging of the real time
gradient signals on the LVDS interface.
10.6.2 Offset Re-Calibration in the Field
During production, the GAB/2 is calibrated for minimum residual offset. This calibration is
normally sufficient for a long time period and a wide temperature range. However, it may
happen in rare circumstances that the dynamic offset compensator reaches its limitations.
This is reported by an error message sent to the TopSpin application.
It is then necessary to go to the page Main | GAB | GAB/2 Service Functions and invoke
the offset calibration again by depressing the button Calibrate Offset .
The other parameters on the GAB/2 Service Page are intended for diagnostic purpose.
Service engineer access rights are necessary for modification - it is however not
recommended to change these parameters under normal circumstances.