Agilent Technologies N3280A External Trigger Connections, Computer Connections, Gpib Interface

Installation - 2

Maintaining Stability

In voltage priority mode, the constant voltage loop has the following three compensation bandwidths:

♦30 kHz, 20 kHz; and 10 kHz

In current limit operation, only two compensation bandwidths are available:

♦30 kHz and 10 kHz

If the output of your unit is being shut down by the oscillation protection circuit because of long load wires or a high Q load impedance, you can reprogram the output compensation bandwidth to try and eliminate the oscillation. As shipped from the factory, the compensation bandwidth is set to 30 kHz.

OVP Considerations

CAUTION: Disabling the OVP protection circuit may cause excessive output voltages, such as can occur if remote sense leads are shorted, to damage the equipment under test.

The dc source is shipped from the factory with its overvoltage protection circuit enabled. You can disable the OVP circuit using the VOLTage:PROTection:STATe command as explained in chapter 6. The overvoltage circuit automatically turns the output off and opens the output relays if the output voltage exceeds +11.5V (±0.3V) or −11.5V (±0.3V)

External Trigger Connections

This rear panel connector has an external trigger input.

The trigger input pin is normally at a TTL high level. To generate a trigger, you can provide a negative- going TTL signal to the trigger input, or momentarily connect a short (contact closure) from the trigger input pin to the chassis ground pin on the trigger connector. In any case, the device that you use to implement the trigger must be able to sink approximately 1mA.

The external trigger input can trigger both output voltage/current changes and output measurements.

Computer Connections

The dc source can be controlled through a GPIB interface.

GPIB Interface

Follow the GPIB card manufacturer's directions for card installation and software driver setup. Dc sources may be connected to the GPIB interface in series configuration, star configuration, or a combination of the two, provided the following rules are observed:

♦The total number of devices including the GPIB interface card is no more than 15.

♦The total length of all cables used is no more than 2 meters times the number of devices connected together, up to a maximum of 20 meters. (Refer to table 1-2 for a list of available GPIB cables.)

♦Do not stack more than three connector blocks together on any GPIB connector.

♦Make sure all connectors are fully seated and the lock screws are firmly finger-tightened.

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