Instrument Control Toolbox

binblockread

Read binblock data from the instrument

Syntax

• A = binblockread(obj)
  A = binblockread(obj,'precision')
  [A,count] = binblockread(...)
  [A,count,msg] = binblockread(...)
  

Arguments

obj	An instrument object.
'precision'	The number of bits read for each value, and the interpretation of the bits as character, integer, or floating-point values.
A	Binblock data returned from the instrument.
count	The number of values read.
msg	A message indicating if the read operation was unsuccessful.

Description

A = binblockread(obj) reads binary-block (binblock) data from the instrument connected to obj and returns the values to A. The binblock format is described in the binblockwrite reference pages.

A = binblockread(obj,'precision') reads binblock data translating MATLAB values to the precision specified by precision. By default the uchar precision is used and numeric values are returned in double-precision arrays. Refer to the fread function for a list of supported precisions.

[A,count] = binblockread(...) returns the number of values read to count.

[A,count,msg] = binblockread(...) returns a warning message to msg if the read operation did not complete successfully.

Remarks

Before you can read data from the instrument, it must be connected to obj with the fopen function. A connected instrument object has a Status property value of open. An error is returned if you attempt to perform a read operation while obj is not connected to the instrument.

binblockread blocks the MATLAB command line until one of the following occurs:

• The data is completely read.
• The time specified by the Timeout property passes.

If msg is not included as an output argument and the read operation was not successful, then a warning message is returned to the command line.

The ValuesReceived property value is increased by the number of values read, each time binblockread is issued.

Example

Create the GPIB object g associated with a National Instruments GPIB controller with board index 0, and a Tektronix TDS 210 oscilloscope with primary address 2.

• g = gpib('ni',0,2);
  g.InputBufferSize = 3000;
  

Connect g to the instrument, and write string commands that configure the scope to transfer binary waveform data from memory location A.

• fopen(g)
  fprintf(g,'DATA:DESTINATION REFA');
  fprintf(g,'DATA:ENCDG SRPbinary');
  fprintf(g,'DATA:WIDTH 1');
  fprintf(g,'DATA:START 1');
  

Write the CURVE? command, which prepares the scope to transfer data, and read the data using the binblock format.

• fprintf(g,'CURVE?')
  data = binblockread(g);
  

See Also

Functions

binblockwrite, fopen, fread, instrhelp

Properties

BytesAvailable, InputBufferSize, Status, ValuesReceived

Functions - Alphabetical List

binblockwrite