Keithley 3720 User Manual page 60

Section 4: Closing and Opening Switching Module Channels
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The number of channel patterns 32K will hold varies with the number of characters stored. If a
given channel pattern name is 5 characters long, and each pattern is comprised of 5 channels
each, with the string image only being comma delimited (for example,
"2003,4003,2005,4005,2915"), then the number of channel patterns capable of being stored is
642. Decreasing the number of characters in each channel pattern name or the number of
channels in the channel pattern image allows room for additional patterns to be stored.
Conversely, increasing the number of characters in the channel pattern name or number of
channels in the channel pattern image will take up additional space, thereby allowing fewer
channel patterns to be stored.
Pole settings and channel patterns
NOTE
When creating a channel pattern image, set the pole setting first (when the pole setting for a
channel is changed, patterns that contain the channel are deleted). For example, assume a
channel pattern called 'myimage' has channels 2004, 2008 and 2012 associated with it while
'myimage2' has channels 2005, 2009 and 2011. Now, if pole setting of Channel 2004 changes
then the channel pattern 'myimage' is deleted and no longer exist in system. However, the
pattern called 'myimage2' still exists.
NOTE
While creating channel pattern images, the paired channel will automatically be accounted for
based on pole setting. Therefore, the paired channel does not need to be specified in the
channel image manually. For example, assume Slot 1 has a 3720 card installed and all
channels are set to 4-pole operation. With all channels configured for 4-pole, the available
channels are 1001 to 1030. To create a channel pattern called 'one4wire' with Channel 1001
and backplane relays 1911 and 1922, the corresponding bus command is:
channel.pattern.setimage('1001, 1911, 1922', 'one4wire')
4-4
are part of saved setup data and restored when a setup is recalled.
are deleted with a system reset or reset of a channel associated with a pattern.
have 32K of memory available for each channel pattern to store data.
Changing a channel's pole setting deletes all patterns containing that channel.
Matrix channels have fixed pole settings. Multiplexer channels pole settings may be
changed.
Series 3700 System Switch/Multimeter User's Manual
Document Number: 3700S-900-01 Rev. A / August 2007