Agilent Technologies VXI E1439 User Manual

Page 173

163

Agilent E1439 Programmer's Reference

Functions listed alphabetically

In continuous data collection mode, wordCount should be set equal to the maximum possible
wordCount to ensure that the entire data block is read out.

overloadPtr

returns an overload indicator.

See “Comments on Overload” on page 160

. The way to properly

use the overload argument for the age1439_read_raw function is this:

1. Set up the hardware.
2. Call

age1439_meas_start

3. Call

age1439_read_raw

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 the

age1439_read_raw

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

Note

The primary purpose of the age1439_read_raw function is to provide the fastest possible way to
read blocks of data from the module. Since this command does not perform data scaling after
reading data it may save 10-20% of the overall age1439_read time, depending on the host
computer in use. The resulting data ordering is dependent on the data type and resolution. The
array may be cast as a long before reading the data to provide whole words.

Example

A declaration in the Front Panel example program can be changed to exercise age1439_read_
raw() in frmMain of e1439.vbp:

Const constFreqCentRaw = False ’when TRUE, use age1439_read_raw()

’instead of age1439_read

Return Value

AGE1439_SUCCESS
AGE1439_NO_DATA_MEASUREMENT_IN_PROGRESS

Data type

Resolution

(bits)

Words per sample

REAL

COMPLEX

This manual is related to the following products:

E1439