Local Operation
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 for 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. This input has a user selectable polarity with logic low input from 0.0V to 1.2V and logic high from 2.0V to 15V. The control signal for this input must be capable of sinking 10mA minimum. This input is also compatible with the use of dry contacts, where a short is logic low and an open is logic high. The input lines of the shutdown circuit are fully optically isolated. See page
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 voltage or dry contact control (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
To activate the shutdown function:
◆Connect 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).
The External Shutdown pin is pulled high internally (normally high). Therefore, if this feature is not used, the polarity should be set to 1 to avoid false triggering. (See “Defining the Polarity of the External Shutdown Signal” on page
