User manual

Section 8: Scanning Series 3700 System Switch/Multimeter Reference Manual
8-16 3700S-901-01 Rev. C / July 2008
-- Set bypass to ON so first channel closes without taking
a measurement.
scan.bypass = scan.ON
-- Make buffer named "mybuffer" and configure it to store
up to 1000 readings.
mybuffer = dmm.makebuffer(1000)
-- Initiate the scan to execute in the background and save
readings to a buffer called "mybuffer."
scan.background(mybuffer)
Example 4:
Optimizing scanning for speed.
Some cards, such as the Model 3723, use relays that are optimized for
switching speed and reliability. However, these cards still use backplane relays
(EMR) that are slow and have a shorter life. Full speed and reliability of the card
can be realized by avoiding scan modes that intelligently open and close
backplane relays (for example, scan.MODE_OPEN_SELECTIVE). By setting the
scan mode (scan.mode) to scan.MODE_FIXED_ABR, all required backplane
relays will be closed prior to the start of the scan and remain closed until you
program them to open.
Here's an example of a Model 3706 configured for fast scanning with the Model
3723 card. Sixty channels will be scanned ten times on 200V DCV.
-- Reset the Series 3700 to factory defaults.
reset()
-- Select active function as DC volts.
dmm.func= 'dcvolts'
-- Turn auto range off.
dmm.autorange=dmm.OFF
-- Select the range based on 200 volts.
dmm.range='200'
-- Turn autozero off.
dmm.autozero=dmm.OFF
-- Set the NPLC to .006.
dmm.nplc=.006
-- Turn auto delay off.
dmm.autodelay=dmm.OFF
-- Create a reading buffer to hold 600 readings.
reading_buffer=dmm.makebuffer(600)
-- Save the current dmm settings as "mydcvolts"
configuration.
dmm.configure.set('mydcvolts')