Overcurrent Protection - Tektronix Keithley 2281 Series Reference Manual

Section 2: General operation

Overcurrent protection

Overcurrent protection restricts the maximum current level that the instrument can source. This
protects the device under test (DUT) from high current levels.
For example, if a sense lead is disconnected or broken during a 4-wire sense measurement, the
instrument can interpret the missing sense lead as a decrease in voltage and respond by increasing
the source output. If overcurrent protection is set, the sourced output is not allowed to exceed the
overcurrent protection limit.
When overcurrent protection is set and the sourced voltage exceeds the setting:
The output is turned off.
On the front panel, an indicator to the right of the voltage displays OCP.
An error is generated. For more information, refer to
When overcurrent protection is used in a test sequence, it should be set before turning the source on.
Even with the overcurrent protection set to the lowest value, never touch anything connected
to the terminals of the 2281S when the output is on. Always assume that a hazardous voltage
(greater than 30 V RMS) is present when the output is on. To prevent damage to the DUT or
external circuitry, do not set the current source to levels that exceed the value that is set for
overcurrent protection.
Setting overcurrent protection limits
To set overcurrent protection using the front panel:
1. Press the MENU key.
2. Under Source, select Protect.
3. Select OCP and set the limit.
4. Select HOME to return to the operating display.
To set overcurrent protection using SCPI commands:
To set the overcurrent limit for the current source to 4 A, send the command:
:CURRent:PROTection 4
See the command description for
the full list of options.
2-102
Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual
[:SOURce[n]]:<function>:PROTection[:LEVel]
Overprotection error (on page 2-103).
(on page 7-129) for
077114601 / March 2019