mempoke
(To be removed) Low-level memory write to VXI register
This visa
object function will be removed in a future release. Use
visadev
object functions instead. For more information, see Compatibility Considerations.
Syntax
mempoke(obj,data,offset)
mempoke(obj,data,offset,'precision')
Arguments
| A VISA-VXI or VISA-GPIB-VXI object. |
| The data written to the memory address. |
| The offset in the mapped memory space to which the data is written. |
| The number of bits to write to the memory address. |
Description
mempoke(obj,data,offset)
writes the
uint8
value specified by data
to the
mapped memory address specified by offset
for the object
obj
.
mempoke(obj,data,offset,'precision')
writes data
using the number of bits specified by
precision
. precision
can
be uint8
, uint16
, or
uint32
, which instructs mempoke
to write
data
as 8-, 16-, or 32-bit values, respectively.
precision
can also be single
,
which instructs mempoke
to write data
as
single-precision values.
Examples
Create the VISA-VXI object vv
associated with a VXI chassis
with index 0, and a Keysight® E1432A digitizer with logical address 130.
vv = visa('keysight','VXI0::130::INSTR'); fopen(vv)
Use memmap
to map 16 bytes in the A16 address space.
memmap(vv,'A16',0,16)
Perform a low-level write to the fourth instrument register, which has an offset of 6.
mempoke(vv,45056,6,'uint16')
Unmap the memory and disconnect vv
from the instrument.
memunmap(vv) fclose(vv)
Tips
Before you can write to the VXI register, obj
must be connected
to the instrument with the fopen
function. A connected
interface object has a Status
property value of
open
. An error is returned if you attempt a write operation
while obj
is not connected to the instrument.
You must map the memory space using the memmap
function before using
mempoke
. The
MappedMemorySize
property returns the size of the memory
space mapped.
offset
indicates the offset in the mapped memory space to which
the data is written. For example, if the mapped memory space begins at 200H, the
offset is 2, and the precision is uint8
, then the data is written
to memory location 202H. If the precision is uint16
, the data is
written to 202H and 203H.
To increase speed, mempoke
does not return error
messages from the instrument.
Version History
Introduced before R2006aSee Also
fopen
| memmap
| mempeek
| MappedMemorySize | MemoryIncrement