Bruker NMR AV4 BSMS System, Руководство пользователя

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14.5.2 Analog Liquid Nitrogen Level Measurement (SPB-E only)
Nitrogen level measurements are performed by a sensor that is encircled by a cylindrical
conductor. The sensor and surrounding conductor form a capacitor. The presence of liquid
nitrogen between the sensor and conductor changes the capacitance, and this is measured
and converted by the sensor electronics into a proportional voltage which is interpreted by the
SPB-E to provide the reading.
The measurement circuit on the SPB-E board is separated galvanically from the other
electronics.
The interface of the SPB-E is fully compatible with all models of Bruker Nitrogen Level
Sensor [ } 195] .
It is recommended to use the digital nitrogen level sensor and connect it to the AUX port of
the SPB-E or the VPSB(-DC). For details see
Nitrogen Level Sensor [ } 195] .
14.5.3 Sample Down and Sample Up Detection
The interface for standard Bruker Shim Upper part (BST) is backward compatible to the
former SLCB circuit. An improved signal processing for the sample down detection allows
reliable detection of the various spinners. Sensor supplies are short circuit proof and wiring
detection allows improved system diagnostic.
14.5.4 Version of the Shim Upper Part
The shim upper part version can be read by the SPB.
Old style shim upper parts (SOT72) using Z12084 CABLE ADAPT BSMS/SOT72 can be
connected to a SPB(-E) ECL02.03 and newer. Because these shim upper parts do not
include a sample up light barrier, reduced functionality (sample lift speed, display) will result.
14.5.5 Sample Changer Interface
The sample changer has its own pneumatic controller. The shim upper part (BST) is
equipped with a light switch to detect whether there is a sample present for pickup. This
information is then passed to the sample changer via the sample changer interface of the
BSMS.
14.5.6 Control Output for BSMS/2 Variable Power Supply Board
The SPB provides 1 (SPB) or 2 (SPB-E) interfaces for connecting BSMS/2 VARIABLE
POWER SUPPLY BOARDS (VPSB). These boards do not have any connections to the
BSMS backplane and all control signals are carried over this interface.
On the interface connector some supply and detection signals and a high speed LVDS-
based digital interface are wired. The LVDS-based interface carries the Synchronous Serial
Rack Bus signals from the ELCB and BSMS backplane over the cable connection to the
control FPGA on the VPSB. The interface is hot-plug capable, has automatic connect/
disconnect detection and power supply signals are short-circuit proof.
Note: The new AV4 VPSB-DC(-E) does not require this interface connector.