
12-18
Return to
2600AS-901-01 Rev. B / September 2008
Section 12: TSP Fundamentals and Script Management
Series 2600A System SourceMeter® Instruments Reference Manual
Restoring a script in the run-time environment
Once a script has been saved, you may want to remove it from the run-time environment to free up
memory. The script may be restored to the run-time environment when needed. To restore the
script to the run-time environment, use the one of the following commands:
script.restore("name")
script.user.restore("name")
Where:
name
is the user-defined name of the script to be restored.
Example:
Restore a user script named
"test9"
from nonvolatile memory:
script.restore("test9")
Memory considerations for the run-time environment
The Series 2600A reserves 32MB of memory for dynamic run-time use. Of this memory, the
firmware requires up to approximately 5MB for general operation. It is recommended that 1MB
always be left free for the instrument's internal needs, and that 2MB be reserved for future
firmware updates. That leaves approximately 24MB of memory available to the user. The run-time
environment, user-created reading buffers, and active sweep configuration must fit within this
24MB of memory.
The amount of memory used by a reading buffer is approximately 15 bytes for each entry
requested. There is a slight amount of overhead for a reading buffer, but this can be ignored for
memory utilization calculations. For example, assume two reading buffers were created. One of
them was created to store up to 1,000 readings and the other 2,500.The memory reserved for the
reading buffers is calculated as follows:
(1000 x 15) + (2500 x 15) = 52,500 bytes or 52.5 kilobytes.
Note that the dedicated reading buffers do not consume memory needed by the run-time
environment. Do not include them in your memory consumption calculations. Also, reading buffers
for remote nodes consume memory on the remote node, not the local node. You should be sure
the total reading buffer memory for any particular remote node does not exceed 24MB, but do not
include that amount in your local memory consumption calculations.
The amount of memory used by a sweep configuration is based on the number of source points.
The actual memory consumption can vary greatly depending on the SMU settings, but as a
general rule each source point can be expected to consume at least 24 bytes.
It is possible for the memory used for these purposes to exceed 24MB. When this occurs, there is
a risk that memory allocation errors will be generated and commands will not be executed as
expected. If memory allocation errors are encountered, the state of the instrument cannot be
guaranteed. After attempting to save off any important data, it is recommended that power to the
instrument be cycled to return it to a known state. Cycling power will reset the run-time
environment.
Unsaved scripts and reading buffers will be lost. The amount of memory in use can be checked
using the
meminfo
function. The first value returned by
meminfo
is the number of kilobytes of
memory in use.
Checking the memory
Use the
meminfo
function to view the available free memory in the instrument (see
for more information).