Configure The Measurement; Configure Triggering - VTI Instruments Metek EX1202 User Manual

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ONFIGURE THE EASUREMENT
A simple DMM measurement can be configured by setting the function, range, and resolution.
There are many other parameters that may need to be configured depending on the type of
measurement being performed. This is explained in detail in later sections.

Function: Selects the measurement type (DCV, DCI, ACV, ACI, 2-wire resistance, 4-wire
resistance, temperature, frequency, or period).

Range: Selects the measurement range. The range should be set to the closest possible range
that is greater than or equal to the value passed as this parameter.

Resolution: Selects the measurement resolution. The fastest aperture time that will provide
this amount of resolution will be selected. If the amount of resolution is not possible, the
longest aperture will be selected.
IVI-COM Programming Interface

The VTEXDmmFunctionEnum interface provides properties and methods for selecting the
measurement function. The IVTEXDmm.Configure interface provides method for setting
the range and measurement function selection.
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ONFIGURE RIGGERING
The EX1200 DMM trigger model is divided into five states: IDLE, INITIATE, WAITING FOR
TRIGGER, WAITING FOR SAMPLE TRIGGER, and ACQUISITION (see Figure 4-3). A
system reset condition puts the EX1200 DMM in the IDLE state. The
begins the acquisition sequence by transitioning the instrument into the INITIATE layer. As this
occurs, the reading buffer memory is cleared.
As soon as the initiate process is complete, the device transitions to the TRIGGER state. The
DMM remains in the TRIGGER state until a specified TRIGGER event occurs. After receiving a
trigger, the DMM will wait the specified trigger delay until it takes a measurement. A delay allows
a signal to stabilize if needed. If a user-configured delay is used, it will override the automatic
trigger delay used by EX1200 DMM. Triggers can also be generated by software commands or
may be set to immediate, which causes a transition from the TRIGGER state to the
ACQUISITION state.
The SAMP TRIGGER acts as a secondary trigger. The same principles that apply to the
TRIGGER state apply to the SAMP TRIGGER state. Using the INTERVAL setting, the DMM
can be configured to take multipoint readings with a defined time interval.
NOTE The first measurement is taken when a Trigger event occurs (along with the corresponding delay)
and that the DMM will not wait for a Sample Trigger to occur per the IVI specification.
Each state has input values which can be set by the user:

Trigger Input Options
Trigger Input Source: sets the trigger line that moves the DMM from the Wait-For-Trigger
Trigger Input Slope: indicates whether a rising or falling edge will move the DMM from the
Trigger Input Count: sets the number of times the Wait-For-Trigger state will be entered
Trigger Delay: indicates the delay that occurs between when the trigger occurs and when the
Auto-Delay: allows the DMM to automatically set the trigger delay based on the
Basic EX1200 DMM Operation
state to the Delay state.
Wait-For-Trigger state to the Delay state.
each time a measurement is initiated.
measurement is actually taken. Valid values are 0 s to 4294.967295 s.
measurement configuration.
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API call
DMM Initiate()
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