Section 7: Introduction to TSP operation Model 2461 Interactive SourceMeter® Instrument Reference Manual7-40 2461-901-01 A/November 2015Memory considerations for the run-time environmentThe Model 2461 reserves a large amount of memory for use with interactions with the front panel,commands, and test scripts. The amount of memory usage is affected by the following productfeatures:• Reading buffers (including local default and user-created reading buffers; if they are on a remotenode, they only affect the remote node)• Lua variables (large arrays)• TriggerFlow trigger models• Configuration listsThe more a feature is used or the larger its definition, the more memory it consumes. For normalusage, reading buffers commonly reserve large amounts of memory. The amount of memory useddepends on the number of readings and the buffer style.The Model 2461 notifies you when the system runs out of memory. If the instrument encountersmemory allocation errors (errors that specifically state “Out of Memory”), the state of the instrumentcannot be guaranteed. After attempting to save any important data, turn off power to the instrumentand turn it back on to reset the runtime environment and return the instrument to a known state.Unsaved scripts and reading buffers will be lost.If you encounter memory problems, examine the test script or SCPI commands that were beingexecuted when the memory problems occurred. Take action to reduce the size of the elements thatare consuming memory. If you are using TSP commands and scripting, also consider using thecollectgarbage() command to clean up unused memory. For information oncollectgarbage(), refer to Base library functions.The default size settings for the default reading buffers (defbuffer1 and defbuffer2) are large. Ifyour application does not use these buffers, you can set them to the minimum of 10 readings toconserve space. For information on adjusting the buffer size, refer to Setting reading buffer capacity.The buffer style is set when you create a user-defined reading buffer. The buffer style cannot bechanged, so to eliminate memory problems caused by the style, you may need to delete or adjust thecapacity of the buffers. Refer to Creating buffers for information on the effects of styles.The amount of memory used by a sweep configuration is based on the number of source points. Theactual memory consumption can vary greatly depending on how often the source-measure unit(SMU) take readings during the sweep, but as a general rule, each source point can be expected toconsume at least 24 bytes.It is possible for the memory used for the run-time environment, sweep configuration, and readingbuffers to exceed 32 MB. When this occurs, there is a risk that memory allocation errors will occurand instrument will not execute commands as expected.About TSP CommandsThis section contains an overview of the TSP commands for the instrument. The commands areorganized into groups, with a brief description of each group. Each section contains links to thedetailed descriptions for each command in the TSP command reference section of thisdocumentation (see TSP commands (on page 8-7)).
