Keithley 2657A User Manual

Section 6: Instrument programming Model 2657A High Power System SourceMeter® Instrument Reference Manual
6-60 2657A-901-01 Rev. B/December 2012
Copying test scripts across the TSP-Link network
To run a large script on a remote node, copy the test script to the remote node to increase the speed
of test script initiation.
The code in the example below copies a test script across the TSP-Link
®
network, creating a copy of
the script on the remote node with the same name.
-- Add the source code from the script
-- testScript to the data queue.
node[2].dataqueue.add(testScript.source)
-- Create a new script on the remote node
-- using the source code from testScript.
node[2].execute(testScript.name ..
"= script.new(dataqueue.next(), [[" .. testScript.name .. "]])")
Removing stale values from the reading buffer cache
The node that acquires the data stores the data for the reading buffer. To optimize data access, all
nodes can cache data from the node that stores the reading buffer data.
Running Lua code remotely can cause reading buffer data that is held in the cache to become stale. If
the values in the reading buffer change while the Lua code runs remotely, another node can hold
stale values. Use the clearcache() command to clear the cache. For additional detail on the
reading buffer cache commands, see bufferVar.cachemode
(on page 7-17) and
bufferVar.clearcache()
(on page 7-19).
The following example code demonstrates how stale values occur and how to use the
clearcache() command to clear the cache on node 2, which is part of group 7.
-- Create a reading buffer on a node in a remote group.
node[2].tsplink.group = 7
node[2].execute("rbremote = smua.makebuffer(20) " ..
"smua.measure.count = 20 " ..
"smua.measure.v(rbremote)")
-- Create a variable on the local node to
-- access the reading buffer.
rblocal = node[2].getglobal("rbremote")
-- Access data from the reading buffer.
print(rblocal[1])
-- Run code on the remote node that updates the reading buffer.
node[2].execute("smua.measure.v(rbremote)")
-- Use the clearcache command if the reading buffer contains cached data.
rblocal.clearcache()
-- If you do not use the clearcache command, the data buffer
-- values will never update. Every time the print command is
-- issued after the first print command, the same data buffer
-- values will print.
print(rblocal[1])

Keithley 2657A Specifications

General

Brand	Keithley
Model	2657A
Category	Measuring Instruments
Language	English