Keithley 2450 Reference Manual page 272

Model 2450 Interactive SourceMeter® Instrument Reference Manual Section 3: Functions and features
You cannot access the reading buffers or global variables from any node in a remote group while a
node in that group is performing an overlapped operation. However, you can use the data queue to
retrieve data from any node in a group that is performing an overlapped operation. In addition, the
master node and the group leaders can use the data queue as a way to coordinate activities.
Tables in the data queue consume one entry. When a node stores a table in the data queue, a copy
of the data in the table is made. When the data is retrieved from the data queue, a new table is
created on the node that is retrieving the data. The new table contains a completely separate copy of
the data in the original table, with no references to the original table or any subtables.
You can access data from the data queue even if a remote group or a node has overlapped
operations in process. See the dataqueue commands in the TSP command reference (on page 8-1)
for more information.
2450-901-01 Rev. B/September 2013 3-127