Instrument Control Toolbox

MemoryIncrement

Specify if the VXI register offset increments after data is transferred

Description

You can configure MemoryIncrement to be block or FIFO. If MemoryIncrement is block, the memread and memwrite functions increment the offset after every read and write operation, and data is transferred from or to consecutive memory elements. If MemoryIncrement is FIFO, the memread and memwrite functions do not increment the VXI register offset, and data is always read from or written to the same memory element.

Characteristics

Usage	VISA-VXI, VISA-GPIB-VXI
Read only	Never
Data type	String

Values

{block}	Increment the VXI register offset.
FIFO	Do not increment the VXI register offset.

Example

Create the VISA-VXI object v associated with a VXI chassis with index 0, and an instrument with logical address 8.

• v = visa('ni','VXI0::8::INSTR');
  fopen(v)
  

Configure the hardware for a FIFO read and write operation.

• set(v,'MemoryIncrement','FIFO')
  

Write two values to the VXI register starting at offset 16. Because MemoryIncrement is FIFO, the VXI register offset does not change and both values are written to offset 16.

• memwrite(v,[1984 2000],16,'uint32','A16')
  

Read the value at offset 16. The value returned is the second value written with the memwrite function.

• memread(v,16,'uint32')
  ans =
  2000
  

Read two values starting at offset 16. Note that both values are read at offset 16.

• memread(v,16,'uint32','A16',2);
  ans =
  2000
  2000
  

Configure the hardware for a block read and write operation.

• set(v,'MemoryIncrement','block')
  

Write two values to the VXI register starting at offset 16. The first value is written to offset 16 and the second value is written to offset 20 because a uint32 value consists of four bytes.

• memwrite(v,[1984 2000],16,'uint32','A16')
  

Read the value at offset 16. The value returned is the first value written with the memwrite function.

• memread(v,16,'uint32')
  ans =
  1984
  

Read two values starting at offset 16. The first value is read at offset 16 and the second value is read at offset 20.

• memread(v,16,'uint32','A16',2);
  ans =
  1984
  2000
  

See Also

Functions

mempeek, mempoke, memread, memwrite

MemoryBase

MemorySize