IVI DMM Acquire

LabVIEW SignalExpress

previous page next page

IVI DMM Acquire

Acquires a signal from an instrument in the Digital Multimeter IVI Class.

Default values are specific to the hardware and driver specified. The default settings may not be applicable to the measurement you are trying to perform. Click the Initialize button, located on the step's toolbar, at any time to reset the step to the default settings.

To communicate with an instrument, you need to install the instrument-specific driver and create a session name for the instrument.

Parameter	Description
Output Display	Displays the measurement, formatted according to the Measurement function, Range, and Resolution.
Configuration	Contains the following configuration options: Device—Contains the following device options: IVI session name—Specifies the session name to use for this step. This step retrieves possible session names from National Instruments Measurement & Automation Explorer (MAX). You also can create a new session or edit/delete an existing session. Resource descriptor—Specifies the interface and the address of the hardware to associate with the step. Instrument driver—Displays the name of the driver in use. Basic Parameters—Contains the following options: Measurement function—Specifies the type of measurement you want the DMM to perform. Options include DC Volts, AC Volts, DC Current, AC Current, 2 Wire Resistance, 4 Wire Resistance, AC + DC Volts, AC + DC Current, Frequency, and Period. Range—Specifies whether Auto Range is used. Contains the following options: Auto Range—Specifies that the DMM automatically calculates the range before each measurement. Specify Range—Allows you to specify the range and uses this value for all subsequent measurements until you change the measurement configuration. Range value (V)—[Measurement function: DC Volts, AC Volts, AC + DC Volts] The range in volts for the current measurement. Range value (A)—[Measurement function: DC Current, AC Current, AC + DC Current] The range in amps for the current measurement. Range value (Ohm)—[Measurement function: 2 Wire Resistance, 4 Wire Resistance] The range in ohms for the current measurement. Range value (Hz)—[Measurement function: Frequency] The range in hertz for the current measurement. Range value (s)—[Measurement function: Period] The range in seconds for the current measurement. Resolution—Specifies the digital resolution of the measurement. Set Range to Specify Range to enable this option. Sample period (s)—Specifies how often to execute the step. Measurement Specific Parameters—Contains the following options: Auto zero—Specifies that the DMM internally disconnects the input signal and takes a zero reading. The DMM then subtracts the zero reading from the measurement to prevent offset voltages present from affecting measurement accuracy. This option does not appear if you set Measurement function to Frequency or Period. Contains the following options: On—Configures the DMM to take a zero reading for each measurement. The DMM subtracts the zero reading from the value it measures. Off—Disables the Auto zero option. Once—Configures the DMM to take a zero reading immediately. The DMM then subtracts this zero reading from all subsequent values it measures. AC min frequency (Hz)—[Measurement function: AC Volts, AC Current, AC + DC Volts, AC + DC Current] Specifies the minimum expected frequency component of the input signal in hertz. AC max frequency (Hz)—[Measurement function: AC Volts, AC Current, AC + DC Volts, AC + DC Current] Specifies the maximum expected frequency component of the input signal in hertz. Frequency voltage range—[Measurement function: Frequency, Period] Specifies whether the frequency voltage Auto Range is used. Contains the following options: Auto Range—Configures the DMM to automatically calculate the voltage range before each frequency or period measurement. Specify Range—Disables auto ranging. The DMM sets the voltage range to the range specified in Frequency range (V). Frequency range (V)—[Measurement function: Frequency, Period] Specifies the expected maximum amplitude of the input signal. The minimum peak-to-peak signal amplitude that the DMM can detect is 10% of the specified voltage range. Powerline Frequency (Hz)—Specifies the powerline frequency in hertz.
Trigger	Contains the following trigger options: Type—Specifies the trigger source you want to use. After the DMM receives the trigger, the DMM waits the length of time you specify in the Delay (s) parameter. The DMM then takes a measurement. The default is Immediate. Contains the following options: Immediate—Does not wait for a trigger of any kind. External—Waits for a trigger on the external input. Software—Waits until you press the associated trigger button in the toolbar. Digital—Waits for a trigger on a digital input specified by the trigger source. Delay (s)—Specifies the length of time the DMM waits after it receives the trigger and before it takes a measurement. Auto—Configures the DMM to automatically calculate the trigger delay before each measurement. Timeout (s)—Configures the amount of time to wait while retrieving a reading from the DMM. The default is 5 seconds. Slope—[Type: External] Specifies whether you want a rising edge or a falling edge passing through the trigger level to trigger the DMM. Contains the following options: Positive—Triggers on the rising edge of the external trigger. Negative—Triggers on the falling edge of the external trigger. Software trigger source—[Type: Software] Specifies the trigger source to which you want the instrument to respond. To activate the trigger, click the associated trigger button in the toolbar. Execution waits until you click the associated trigger button in the toolbar. Contains the following options: Trigger A—(Default) Specifies Trigger A as the trigger source. Trigger B—Specifies Trigger B as the trigger source. Trigger C—Specifies Trigger C as the trigger source. Source—[Type: Digital] Specifies the trigger source you want to use. Contains the following options: PXI TRIG0 or VXI TTL0—Waits until it receives a trigger on the PXI TRIG0 line (for PXI instruments) or the VXI TTL0 line (for VXI instruments). PXI TRIG1 or VXI TTL1—Waits until it receives a trigger on the PXI TRIG1 line (for PXI instruments) or the VXI TTL1 line (for VXI instruments). PXI TRIG2 or VXI TTL2—Waits until it receives a trigger on the PXI TRIG2 line (for PXI instruments) or the VXI TTL2 line (for VXI instruments). PXI TRIG3 or VXI TTL3—Waits until it receives a trigger on the PXI TRIG3 line (for PXI instruments) or the VXI TTL3 line (for VXI instruments). PXI TRIG4 or VXI TTL4—Waits until it receives a trigger on the PXI TRIG4 line (for PXI instruments) or the VXI TTL4 line (for VXI instruments). PXI TRIG5 or VXI TTL5—Waits until it receives a trigger on the PXI TRIG5 line (for PXI instruments) or the VXI TTL5 line (for VXI instruments). PXI TRIG6 or VXI TTL6—Waits until it receives a trigger on the PXI TRIG6 line (for PXI instruments) or the VXI TTL6 line (for VXI instruments). PXI TRIG7 or VXI TTL7—Waits until it receives a trigger on the PXI TRIG7 line (for PXI instruments) or the VXI TTL7 line (for VXI instruments). ECL0—Waits until it receives a trigger on the VXI ECL0 line. ECL1—Waits until it receives a trigger on the VXI ECL1 line. PXI Star—Waits until it receives a trigger on the PXI STAR trigger bus. RTSI 0—Waits until it receives a trigger on RTSI line 0. RTSI 1—Waits until it receives a trigger on RTSI line 1. RTSI 2—Waits until it receives a trigger on RTSI line 2. RTSI 3—Waits until it receives a trigger on RTSI line 3. RTSI 4—Waits until it receives a trigger on RTSI line 4. RTSI 5—Waits until it receives a trigger on RTSI line 5. RTSI 6—Waits until it receives a trigger on RTSI line 6.
Execution Control	Contains the following execution control options: Start this step after—Makes the step wait until another step has started before executing. You can make the step wait on any other hardware step in the project by selecting the step to wait on from the pull-down menu. You can use this option to force an acquisition device to start after a generation device starts. You also can use this option to ensure that a device generating a trigger signal starts after the device receiving the signal, which avoids sending the signal before the receiver is ready. Step to wait for—Lists the possible steps for which this step can wait. Pre-execution delay (ms)—Specifies the amount of time to wait before the step executes. If you configure the step to start after another step, the delay represents the amount of time to wait after the specified step starts. Post-execution delay (ms)—Specifies the amount of time to wait after the step executes.

previous page start next page