Agilent Technologies DP211 External Trigger Output DP1400 & DC271-FAMILY, Frequency Counter mode

Page 38

will be in the range [0 V, 0.7 V] and the high level in the range [1.7 V, 3.3 V] for HiZ. The high level output will typically give 0.8 V into 50 Ω. The I/O A or B connectors can be used for an Enable trigger input or the following output signals: 10 MHz reference clock, Acquisition skipping to next segment, Acquisition is active, Trigger is armed.

3.9.External Trigger Output (DP1400 & DC271-FAMILY)

When the digitizer is ready to be triggered and a valid trigger signal occurs, a trigger output is generated for external use. It is always available on the Front Panel Trigger Out MCX or MMCX connector. The pulse ends when the data acquisition for the trigger in question is complete.

NOTE: The External Trigger Output functionality is implemented in the hardware. No Trigger Out signal occurs for software-generated triggers such as those of the AUTO mode of AcqirisLive or through the use of the function AcqrsD1_forceTrigger. However, AcqrsD1_forceTriggerEx does generate the signal.

Trigger Output Block diagram:

Signal: 1.6V swing

 

 

50 Ohm

 

 

0v centered

 

G=1

 

 

 

Trigger Out

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The output swing is 1.6 V (±

 

 

 

0.8

V)

when unloaded and 0.8 V when

Offset: +/-2.5 V

 

 

 

 

 

and

fall

terminated on 50 Ω. The rise

 

 

 

 

 

 

times are 2.5 ns typical. The offset can be adjusted, by software control in the range [–2.5 V, +2.5 V] unloaded, or [-

1.25 V, +1.25 V] into 50 Ω. The maximum output current

 

GND

 

 

+5V

 

 

 

 

 

 

 

capability is ± 15 mA. As the output is retro-terminated, it is

 

 

R

ECL

 

R

TTL

 

 

 

 

 

 

possible to drive a 50 Ω line unterminated (HiZ) without loss of

 

 

Signal

 

signal

 

 

 

220

performance.

 

68

 

 

 

For a TTL compatible signal, set the offset to 1.0 V and the

Trigger

 

 

 

Trigger Out R

 

Out

 

 

 

 

 

R

 

With

68

 

swing at destination will be +0.2 to +1.8 V.

With

220

 

 

 

 

 

Offset

 

 

 

Offset

 

 

 

For an ECL compatible signal, terminated on 50 Ω to –1.2 V,

 

 

 

+1.18V GND

 

-1.18V

 

 

 

 

-5V

 

 

 

 

 

 

 

set the offset to –1.2 V and the output will be in the range [–0.8

 

 

 

 

 

 

 

 

V, –1.6 V]).

Alternatively, to reduce the current drawn from the digitizer, the terminations shown here can be used:

For the DC135/DC140/DC211/DC211A/DC241/DC241A/DC271/DC271A/DC271AR modules, a standardized trigger out signal can also be routed to the PXI Bus Star Trigger line.

3.10.Frequency Counter mode

The new DC140 and DC135 digitizers offer an optional Frequency Counter (FC) mode. This option allows the measurement of the average frequency or period of a signal for frequencies up to 400 MHz over a user-selectable aperture between 1 ms and 1000 s. The accuracy is limited by that of the timebase, < 2 ppm; the short term stability is of ~ 0.1 ppm. The accuracy can be improved if an appropriate external reference clock is used. Frequencies in excess of 100 MHz will be measured using the HF divide by four feature of the trigger circuit.

A digitizer with the FC option can also totalize the number of triggers during a chosen time interval or a user- provided gate signal. This can be done for trigger frequencies under 125 MHz and for total counts up to 248. The time interval is measured using the same clock as is being used to drive the digitizer. The user gate signal has to be made available on one of the Control I/O inputs.

User Manual: Family of 8-bit Digitizers

Page 38 of 66

Image 38
Contents Agilent Acqiris Family BIT Digitizers XZ001USA Contents OUT of the BOX Running the Acqirislive Application Conventions Used in This Manual Using this ManualMessage to the User Disclaimer and Safety Packaging and HandlingWarranty System RequirementsMaintenance Transport & ShippingCleaning Disposal and RecyclingIC414 Installation 1. IC414 Hardware installation hints 2. IC414 Windows software installationMultiple Versions Installing the Software under WindowsInstallation Page Page Page Page Page Page Page Page Page Installing the Software for Linux Kernel Mode Driver Compilation ƒ cd linuxdriverpciEnvironment variables for the Firmware Installing the HardwareSpecial cases After Restarting Windows Windows XPPage LabVIEW RT Installing the IVI-COM/C Driver Distribution for Windows 2000/XP and LinuxDP110 Block Diagram OverviewInput Protection Channel Input CouplingImpedance Mezzanine Front-endOffset Particularities DC Accuracy and Linearity Vertical ResolutionInput Voltage and Offset Using Probes Data AcquisitionSingle and Sequence Acquisition Modes Sampling RateAcquisition Memory Combining channels TimingTimebase Range TriggerEdge Trigger Slope Trigger CouplingTrigger Level Window TriggerExternal Clock and Reference Pre- and Post-Trigger DelayTrigger Status Special Front Panel Input and OutputDP1400 & DC271-FAMILY Internal CalibrationASBus Frequency Counter mode External Trigger Output DP1400 & DC271-FAMILYPCI DMA Safety Operating TemperatureDimensions Environmental and PhysicalRunning the AcqirisLive Application Getting Started with AcqirisLiveControl Panel Mode Control Panel and FunctionsDisplaying Multiple Traces Input Voltage Scale, Offset and Coupling Numeric EditorKeyboard shortcuts Acquisition Mode Using digitizers of different models simultaneously Timebase and MemoryDisplay Features, Zoom and Persistence Segmented MemoryStore, Autostore and Conversion of Waveforms SetupTop Line Menu of AcqirisLive Page External 10 MHz Reference and External Clock CalibrateCombine channels Additional Waveform InformationAvailable Switches Display FeaturesCommand Line Switches Operation ModeBanks for Smar Transient Recorder modeBuffer size CalibrationAcquisition State Simulation ModeTemperature Update Multi-instrumentsWho needs a Geographical Map of Modules When should the GeoMapper Application be usedHow to run GeoMapper Page Page Page Appendix B ASBus2 for PCI Digitizers Page Page Page Page Page Appendix H XP104 Fan Unit for DP1400 Page Appendix I XP105 Fan Unit for DP1400