Agilent Technologies N3280A manual Overvoltage Protection, Output Current, Output Mode

5 - Programming the DC Source

Overvoltage Protection

The dc source will turn off its output and open the output relays if the output voltage exceeds +11.5V ( ±0.3V) or −11.5V ( ±0.3V) when measured at the output terminals. Overvoltage protection is only available when operating in voltage priority mode. It is enabled with:

VOLT:PROT:STAT<bool>,(@<channel list>) where <bool> is the protection state (0 OFF; 1 ON).

CAUTION: If overvoltage protection is disabled, the dc source or the equipment under test will not be protected from excessive external voltages.

Output Current

When operating in voltage priority mode, the dc source has a programmable current limit, which applies to both positive and negative output currents. The command to program the current limit is:

CURR:LIM <n>,(@<channel list>) where <n> is the current limit in amperes.

If the load attempts to draw more current than the programmed limit, the output voltage is reduced to keep the current within the limit.

To query the maximum output current limit that can be programmed, use:

CURR:LIM? MAX,(@<channel list>)

When operating in current priority mode, the dc source has a programmable output current. The maximum output current that can be programmed in current priority mode is ±0.5125 mA. The command to program the current is:

CURR <n>,(@<channel list>)

To query the programmed output current setting for output 1, use:

CURR?,(@<channel list>)

Output Mode

You can program the unit to operate in either voltage priority or current priority mode. In voltage priority mode the output is controlled by a constant voltage feedback loop, which maintains the output voltage at its programmed setting. In current priority mode the output is controlled by the constant current feedback loop, which maintains the output load or source current at its programmed setting.

Use the following command to configure the output mode:

FUNC:MODE <mode>,(@<channel list>)

where <mode> is the operating mode (VOLT CURR)

NOTE: If the output is on, changing the output mode will cause the output to turn OFF, cycle modes, and then turn ON. Also, there is no interaction or coupling between modes. Switching back and forth between modes does not change the programmed values.

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