Plug in module

Serviceability. ServiceabiUty is defined as the degree of ease (or difficulty) with which a system can be repaired. This measure specifically considers fault detection, isolation, and repair. RepairabiUty considers only the actual repair time, and is defined as the probabiUty that a failed system is restored to operation in a specified interval of active repair time. Access covers, plug-in modules, or other features to allow easy removal and replacement of failed components improve the repairabihty and serviceabihty (see also Electrical connectors). 

Decoupling tends to introduce much more separation between concepts than is typically found in an analysis. For example, any aspect of an object s behavior that could conceivably be varied tends to get delegated to a separate plug-in module. Thus, we end up with many more types of objects than were mentioned in the specification. Nevertheless, our refinement techniques (see Chapter 6, Abstraction, Refinement, and Testing) enable us to keep the traceability between the two models. 

XMVB can be used as a stand-alone program that is freely available from the author (email weiwu xmu.edu.cn website http //ctc.xmu.edu.cn/ xmvb/). It can also be used as a plug-in module in GAMESS(US) (64). 

There are a number of potential pitfalls in the operation of a boxcar integrator and therefore a brief discussion of some of the operating principles is appropriate. A commonly used boxcar is the PARC Model 162 which, together with its associated plug-in modules, will be used as an example in the following discussion. 

The rays reach the sample detector via an interference filter. A reference detector receives the rays reflected by the wall of the Ulbricht s sphere. The concentration of the analyte can be inferred from the difference between the two reflectance values. In addition, by this formation of difference values the optical system equalizes fluctuations of the xenon flashlight. A sapphire window placed before the sample and reference detector minimises excessive evaporation of surface moisture from the test area of the test strip. The interference filter, which is also situated before the detectors, is method-dependent and is inserted into the instrument with the plug-in module (Fig. 47). 

Fig. 7.6.8 Photo of the partially opened plug-in module showing the bypass shape...

Fig. 7.6.16 Plug-in module with integrated protection for increased robustness. The bypass shape with deflection edge is shown. Dirt and water are separated from the first path of the bypass, which is used for metering the air mass, by inertia effects...

The supply of the individual drives occurs from the plug-in modules via motor cables laid in bundles in cable routes and ending at the terminal box of the electric motors. 

Some NIM power supplies are delivered in the form of a plug-in module these usually have current specifications much less than a normal behind-the-crate supply. Furthermore, some of the module connectors in the crate are not supplied with the mains power, so a plug-in module, in such a case, would not work. 

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