Évaluations - 3, GPA: 4.3 ( )

Fabricant : Agilent Technologies Taille : 3.05 mb Nom Fichier : Langue d'enseignement:

first sample control is ignored). When saving data to file, you will be prompted for a maximum number of segments per file. Banks for SMAR Some of the 10-bit Family modules are capable of acquiring data and being read out simultaneously. The -Bn option allows the internal memory of the digitizer to be divided into n banks. To observe the improved acquisition trigger rate achievable in this mode it is suggested to set up the desired conditions and then turn the event display off. The trigger out signal can be used to monitor the trigger rate; an interval width trigger can be used to check if triggers are missing. Calibration Before operation, the instruments must undergo an internal calibration. As this calibration can only proceed sequentially for each channel, the initialization time of AcqirisLive can become significant for systems with many channels. Therefore, it can sometimes be desirable to be able to start the application quickly by skipping the calibration (which must then be done "manually" before collecting correct data). DMA Data Transfers By default, data transfers on the PCI bus between the digitizer memory and the PC are done in DMA (Direct Memory Access) mode, which allows the fastest transfer speeds (up to about 130 MB/s peak, 100 MB/s sustained acquisition data rate). These very high data rates are not well supported by all hardware configurations (PC motherboard), and system hangs due to endless retries on the PCI bus have been observed on some machines. Such problems disappear when switching DMA mode off (data transfer rate is then about 2.8 MB/s). Please note that switching DMA data transfer mode off precludes the use of acquisition interrupts. The –i switch will therefore be ignored when –n is used. Process Priority When the program checks for an event from the operating system (e.g. to react to user input), it can put itself to sleep for a specified period of time. This gives other applications more processor time, but limits the performance of AcqirisLive in terms of maximum acquisition rate. The default is not to go to sleep, but this can be overridden to allow better performance for other applications. Note that this sleep policy is only in effect while the acquisition is running. When the acquisition stops, the sleep policy is always reset to the longest sleep period. Acquisition Interrupts When performing acquisitions, there are 2 possible ways to wait for the acquisition to complete: polling or using a hardware interrupt. • -p Polling: AcqirisLive runs as a single thread process. After an acquisition is started, the instruments are regularly polled to check when the acquisition is complete. The user interface is still alive, but the latency for reading the data after the acquisition may vary. • -i Hardware interrupt: In this mode, AcqirisLive is run as a multi-thread process. After starting an acquisition, a new thread is created to wait for the hardware interrupt indicating that the acquisition completed. This thread is put to sleep, and wakes up upon reception of the interrupt from the instrument, or after a 2 seconds timeout. Please note that switching the DMA data transfer mode off precludes the use of acquisition interrupts. The –i switch will therefore be ignored when –n is used. Transient Recorder mode The application will start in the Transient Recorder mode as opposed to the oscilloscope mode Simulation Mode Simulation mode allows you to run AcqirisLive without having any digitizer installed in the PC. Temperature Update The internally measured temperature of the currently selected module is normally displayed. Using this switch turns this feature off. Acquisition State This switch turns on the display of the current acquisition state (Stopped, Ready, Started, Reading, Data ready). This is helpful when running with time-consuming settings (e.g. many segments overlaid, many channels, large records, etc.), but will slow down the overall performance. Multi-instruments By default, AcqirisLive tries to detect instruments connected through ASBus, and will initialize any connected digitizers as a multi-instrument. This behavior can be inhibited by the -x switch, in which case any ASBus connector will be ignored. 5. Running the GeoMapper Application 5.1. Who needs a Geographical Map of Modules The GeoMapper application gives the user the possibility of telling the Acqiris driver crucial details of the physical position of modules when this information cannot be deduced directly. It allows the driver to correctly adjust trigger and clock delays between the different modules of an ASBus multi-Instrument and arrange the modules in an intuitive order. The GeoMapper application has been implemented as a Wizard with the goal of learning the physical position of each module of a multi-bus system. The driver already knows the logical Bus and logical Slot numbers of each Acqiris unit present. However, because of varying conventions for the compactPCI slot arrangement on a bus, this is no...

Téléchargez votre

Pour télécharger, entrez 2 chiffres :