Agilent E1439 Programmer's Reference

 

Functions listed alphabetically

 

Parameters

id

is the VXI instrument session pointer returned by the age1439_init function.

data

is a pointer to the array into which the floating point data is to be placed. Be sure to allocate

 

sufficient storage space at this location to hold the full data record as determined by the

 

sampleCount parameter. Note that when the module is set to complex data type, the output data

 

record contains 2 × sampleCount floating point values. For real data the record contains

 

sampleCount floating point values.

sampleCount

for age1439_read sampleCount is the number of real or complex data values to read. Real data is

 

one 32-bit floating point value. Complex data is made up of two 32-bit floating point values

 

comprising the real and imaginary values.

 

for age1439_read64 sampleCount is the number of real or complex data values to read. Real data

 

is one 64-bit floating point value. Complex data is made up of two 64-bit floating point values

 

comprising the real and imaginary values.

 

This should never be set larger than the blocksize parameter set in the age1439_data_blocksize

 

function. In continuous data collection mode, sampleCount should be set equal to blocksize to

 

ensure that the entire data block is read out.

overloadPtr

returns an overload indicator. The way to properly use the overload argument for the age1439_

 

read or age1439_read64 function is this:

 

1. Set up the hardware.

 

2.

Call age1439_meas_start.

 

3.

Call age1439_read or age1439_read64.

 

If data is not available, the read function returns immediately with one of the following return values, and

 

the overload indication is AGE1439_OFF:

AGE1439_NO_DATA_MEASUREMENT_IN_PROGRESS

AGE1439_NO_DATA_MEASUREMENT_PAUSED

AGE1439_NO_DATA_WAITING_FOR_TRIGGER

AGE1439_NO_DATA_WAITING_FOR_ARM

When data is available, AGE1439_SUCCESS is returned and the overload value reflects whether an overload was encountered for the given data block.

4. In continuous mode, subsequent data blocks can be read by calling a age1439_

read or age1439_read64 function again (age1439_meas_start should not be called

again).

5.When used in this way, an overload indication is given for each and every data block read in block mode. In continuous mode the overload indicator only means there was an overload sometime after calling age1439_meas_start.

Comments on Overload

Since reading the status register clears the overload bit, overloads are tracked at the API level.

In block mode, you receive the meas_start and age1439_read

overload indication on a block-by block basis by calling age1439_ in sequence.

In continuous mode, depending on the effective sample rate of the instrument and how often data is read, an overload indication returned by age1439_read may or may not correspond to the data returned. The overload indication only means that an overload has occurred since the most recent

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Agilent Technologies E1439 Data, SampleCount, OverloadPtr, Read or age1439read64 function is this, Call age1439measstart