Making measurements – AMETEK Lx Series II Programming Manual User Manual
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Programming Manual
Lx \ Ls Series II
139
where
number of output points. If a dwell list has only one value, that value will be applied to all points in
the output list. After each new output level or point is programmed, the output remains at that
point in the list for the programmed dwell interval before the list advances to the next point. Only
an ABORt command can transfer the system out of the Dwelling state.
At the end of the dwell interval, the transition to the next state depends on whether or not the list
has completed its sequencing and the state of the LIST:STEP command (see Figure 6-2).
If the list is completed, the trigger system returns to the Idle state.
If the list is not completed, then the system reacts as follows:
LIST:STEP ONCE programs the trigger system to return to the Initiated state to wait for the
next trigger.
LIST:STEP AUTO programs the trigger system to immediately execute the next list point.
6.8
Making Measurements
The AC source has the capability to return a number of current, voltage, and power
measurements. When the AC source is turned on, it is continuously sampling the instantaneous
output voltage and current for several output cycles and writing the results into a buffer. The buffer
holds 4096 voltage and current data points.
The AC source uses the data from the voltage and current buffer to calculate the requested
measurement information. Data in the voltage and current buffers is always re-acquired for
subsequent measurement requests. There are two ways to make measurements:
Use the MEASure commands to immediately start acquiring new voltage and current data,
and return measurement calculations from this data as soon as the buffer is full. This is the
easiest way to make measurements, since it requires no explicit trigger programming.
Use an acquisition trigger to acquire the voltage and current data from the buffer. Then use
the FETCh commands to return calculations from the data that was retrieved by the
acquisition trigger. This method gives you the flexibility to synchronize the data acquisition
with an external signal. FETCh commands do not trigger the acquisition of new measurement
data, but they can be used to return many different calculations from the data that was
retrieved by the acquisition trigger.
Making triggered measurements with the acquisition trigger system is discussed under "Triggering
Measurements".
Note
For each MEASure form of the query, there is a corresponding query that begins with the
header FETCh. FETCh queries perform the same calculation as their MEASure
counterparts, but do not cause new data to be acquired. Data acquired by an explicit
trigger or a previously programmed MEASure command are used.
6.8.1 Voltage and Current Measurements
To read the sum of ac and dc components of the rms voltage or current, use:
MEASure:VOLTage:ACDC? or
MEASure:CURRent:ACDC?
To measure the dc voltage or current components, use:
MEASure:VOLTage:DC? or