Using the External Shutdown Function
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Using the External Shutdown Function
Use the external shutdown function to enable or disable the output of the
power supply via a logic level signal. When the external shutdown is
triggered, the power supply will display SD POL on the output voltage and
current displays and the ALARM LED will illuminate. The external
shutdown is useful for making adjustments to either the load or the power
supply without shutting off the power supply or using the power supply as
part of a larger test system in which digital or analog control is required.

Activating the External Shutdown Function

To activate the external shutdown function, use the AUX output supply
provided on the Analog Programming Connector J3. Transistor-transistor
logic (TTL) or CMOS compatible signals should be used to control this
feature. The input lines of the shutdown circuit are fully optically isolated.
See “Specifications” on page C–1.
Once the External Shutdown has been triggered, the display will blink the
SD POL and the ALARM LED will be illuminated.

Controlling the External Shutdown Function

The external shutdown circuit accepts a TTL or CMOS-compatible signal
(high or low logic level) to enable or disable the power supply output.
Make connections for the signals at the AUX Output and Isolated Analog
Programming Connector on the rear panel. (See “AUX Output and
Isolated Analog Programming (ISOL) Connector” on page 4–19 for more
information.)
To activate the shutdown function:
uConnect the control signal source to the Shutdown pin (J3.12) on the
Aux Output and Isolated Analog Programming Connector with the
control circuit ground connected to Isolated Ground pin (J3.6).

Defining the Polarity of the External Shutdown Signal

1. Turn the mode control knob to the PRT position or press the Rotary
knob/Enter button if the control knob is already at the PRT position.
PrO OUP is displayed on the output voltage display.
2. Turn the Rotary knob/Enter button until PrO SD is displayed.