Tektronix Keithley SourceMeter 2450 User Manual page 88

Section 8: Rechargeable battery measurements Model 2450 SourceMeter® Instrument User's Manual
The TSP code in this example also saves all of the current, voltage, and time readings to a USB flash
drive connected to the 2450 front panel.
Before connecting the battery to the output terminals, complete the following tasks to prepare the
2450 for the test.
Reset the instrument:
1. Press the MENU key.
2. Under System, select Info/Manage.
3. Select System Reset.
4. Select OK.
Set the output-off state to High Impedance:
1. Press the MENU key.
2. Under Source, select Settings.
3. Set Output Off to High Impedance.
The High Impedance output-off state opens the output relay when the output is turned off, which
prevents the battery from draining.
Send the following TSP commands for this example application:
-- This code discharges a 2500 mAH 1.2 V battery to 0.9 V with a
-- discharge current of 2.5A (1C).
-- Before using this code, reset the instrument from the front panel
-- and set the output-off state of the 2450 to High Impedance
-- (High Z). Also, insert a USB flash drive in the front-panel USB
-- port to save your readings.
-- Clear the buffer.
defbuffer1.clear()
-- Measurement settings.
smu.measure.func = smu.FUNC_DC_CURRENT
smu.measure.range = 2.5
smu.measure.sense = smu.SENSE_4WIRE
-- Source settings.
smu.source.func = smu.FUNC_DC_VOLTAGE
smu.source.offmode = smu.OFFMODE_HIGHZ
smu.source.level = 0.9
smu.terminals = smu.TERMINALS_REAR
smu.source.range = 0.9
smu.source.readback = smu.ON
smu.source.ilimit.level = 2.5
-- Set the voltage limit for the battery to stop discharging.
-- Set the variable for the number of iterations.
voltLimit = 0.9001
iteration = 1
-- Turn on the source output.
smu.source.output = smu.ON
8-10 2450-900-01 Rev. E / August 2019