Range And Digits Programming Example; Speed - Keithley 2500 User Manual

Models 2500 and 2502 User's Manual

Range and digits programming example

Table 6-3
2500 is set up as follows:
• Channel 1 auto range: ON
• Channel 1 upper range limit: 2mA
• Channel 1 lower range limit: 200nA
• Display digits 5
Table 6-3
Range and digits programming example
*RST
:SOUR1:VOLT 10
:SENS1:CURR:RANG:AUTO ON
:SENS1:CURR:RANG:AUTO:ULIM 2e-3
:SENS1:CURR:RANG:AUTO:LLIM 200e-9
:DISP:DIG 5
:OUTP1 ON
:READ?
:OUTP1 OFF

Speed

The Speed/Accuracy menu is used to set the integration time of the A/D converter (period
of time the input signal is measured). The integration time affects the usable digits, the
amount of reading noise, and the ultimate reading rate of the instrument. The integration
time is specified in parameters based on the Number of Power Line Cycles (NPLC), where
1 PLC for 60Hz is 16.67msec (1/60) and 1 PLC for 50Hz is 20msec (1/50).
In general, the fastest integration time (FAST; 0.01 PLC) results in increased reading noise
and fewer usable digits. The slowest integration time (HI ACCURACY; 10 PLC) provides
the best common-mode and normal-mode noise rejection. In between settings are a com-
promise between speed and noise. The default power-on speed setting is NORMAL
(1 PLC).
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
TestEquipmentDepot.com
shows a programming example for controlling range and digits. The Model
Command
Range, Digits, Speed, and Filters
Description
Restore GPIB defaults.
Source 10V on Ch. 1.
Enable Ch. 1 auto range.
2mA upper range limit.
200nA lower range limit.
5 display digits.
Turn on output.
Trigger and acquire reading.
Turn off output.
6-5